KR102005377B1 - Integrated Molten Carbonate Fuel Cell and Manufacturing Thereof - Google Patents

Abstract

The present invention relates to a monolithic molten carbonate fuel cell capable of sealing (sealing) a fuel cell without using a thin sheet metal (Wet Seal) by minimizing the step between the matrix by forming the fuel electrode, the matrix and the air electrode integrally, and a manufacturing method thereof will be. (A) a matrix having grooves formed on one side or both sides thereof; (b) a fuel electrode inserted in one side groove of the matrix; And (c) an air electrode inserted into the other side groove of the matrix or coupled to the other side of the matrix.

Description

[0001] The present invention relates to an integrated molten carbonate fuel cell,

The present invention relates to an integrated molten carbonate fuel cell and a method of manufacturing the same. More particularly, the present invention relates to an integrated molten carbonate fuel cell and a method of manufacturing the same. More particularly, And more particularly, to a monolithic molten carbonate fuel cell capable of sealing.

The conventional molten carbonate fuel cell comprises a fuel electrode, a matrix, and an air electrode, and is composed of a separate electrode manufacturing process and a sub-assembly process for assembling the manufactured electrode (see FIGS. 1 to 3). Details of the manufacturing process of each component are as follows.

Fuel electrode manufacturing process: It is made into a sheet form by a tape casting process through a slurry process in which an anode material powder, an organic binder, and a dispersant are mixed with an organic solvent. The produced sheet is laminated with nickel mesh or two or more sheets through a lamination process and then cut to size.

Matrix manufacturing process: The slurry process is performed in the same process as the fuel electrode, and the sheet is made into a sheet by a tape casting process.

Air electrode manufacturing process: Nickel powder is applied to a graphite plate and sintered to complete sintering. The electrolyte is coated thereon and re-sintered to melt and impregnate the electrolyte.

Assembly process: Each component is laminated on a separator to supply electricity and gas to complete the final electrode.

When the electrodes are assembled by the above method, generally, the size of the matrix is made larger than that of the fuel electrode and the air electrode, so that a step is generated in the step of laminating the respective components (FIG. This step may cause sealing problems, and the stress distribution may become non-uniform, causing cracks and the like. To solve this problem, a metal part called a separate sheet metal (wet seal) is added to correct each step, . These thin metal plates are separately required for fuel electrode and air electrode, and the thickness of the fuel electrode is equal to the thickness of the fuel electrode and that for the air electrode is equal to the thickness of the cathode electrode.

However, as shown above, it is necessary to separately prepare sheet metal for each air electrode and fuel electrode, and since it is necessary to assemble in accordance with the order, the manufacturing cost of the molten carbonate fuel cell is increased by using the sheet metal.

In order to solve the above-mentioned problems, the present invention provides a monolithic molten carbonate fuel cell capable of minimizing a level difference between components and sealing without using a thin metal sheet, and a method of manufacturing the same.

In order to solve the above-described problems, the present invention according to a first aspect provides a method of manufacturing a semiconductor device, comprising: (a) a matrix having grooves formed on one side or both sides; (b) a fuel electrode inserted in one side groove of the matrix; And (c) an air electrode inserted into the other side groove of the matrix or coupled to the other side of the matrix.

A concavo-convex structure or a wave structure may be formed on the contact surface between the matrix and the anode or the contact surface between the matrix and the anode.

The matrix may be a square having a length of 50 to 200 mm on one side and a square groove having a side length of 40 to 190 mm on both sides.

According to a second aspect of the present invention, there is provided a method of manufacturing an air electrode, comprising the steps of: (a) preparing an air electrode by supplying a powder mixture for an air electrode to a mold, or injecting mixed powder for the air electrode into a mold; (b) preparing an air electrode-matrix combination body by binding a matrix for a matrix to the air electrode, supplying a mixed powder for a matrix and then applying pressure thereto, or injecting mixed powder for a matrix into a molding frame; (c) combining the fuel electrode mold with the air electrode-matrix combination body manufactured in the step (b), supplying the mixed powder for the fuel electrode, and then injecting the mixed powder for the fuel electrode into the mold, Producing; And (d) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly.

In addition, the present invention according to a third aspect provides a method of manufacturing an air electrode, comprising the steps of: (a) preparing an air electrode by supplying a mixed powder for an air electrode to a mold, or by injecting mixed powder for an air electrode into a mold; (b) supplying a mixed powder for a matrix to a mold, and then pressurizing the mixture; or injecting a mixed powder for a matrix into a mold to produce a matrix; (c) preparing a fuel electrode by supplying mixed powder for fuel electrode to a mold and then injecting mixed powder for fuel electrode into a mold; (d) combining and integrating the formed air electrode, the matrix, and the fuel electrode; And (e) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly.

(I) polyvinyl butyral (PVB), polyvinyl alcohol (PVA) or an acrylic resin as an organic binder; (ii) natural wax, paraffin wax, polyethylene wax or carnauba wax as a lubricant (wax); And (iii) stearic acid or oleic acid as the dispersing agent.

The step (a), the step (b) or the step (c) may be carried out at a pressure of 10 to 100 kg / cm 2 and at a temperature of 60 to 150 ° C. for 10 seconds to 5 minutes. / Cm < 2 > and a temperature of 60 to 200 DEG C, and the extraction can be taken out at a temperature of 60 DEG C or lower.

Since the molten carbonate fuel cell according to the present invention has an integral structure, it is possible to manufacture a fuel cell without using a wet metal sheet, so that the post-process by welding is minimized and the defect rate is reduced. Can be manufactured using the same manufacturing process, so that the production process is simplified, so that it is possible to produce an economical fuel cell.

1 to 3 are schematic views of a method of manufacturing a molten carbonate fuel cell according to a conventional method.
4 is a schematic view showing a method of manufacturing a molten carbonate fuel cell according to an embodiment of the present invention.
5 is a schematic view showing a method of manufacturing a molten carbonate fuel cell according to another embodiment of the present invention.
6 is a graph comparing (a) an existing molten carbonate fuel cell and (b) a molten carbonate fuel cell according to an embodiment of the present invention.
7 is a schematic view showing a plan view and a cross-sectional view of a molten carbonate fuel cell according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. Throughout the specification, when an element is referred to as "including " an element, it means that it can include other elements, not excluding other elements, unless specifically stated otherwise.

(A) a matrix having grooves formed on one side or both sides thereof; (b) a fuel electrode inserted in one side groove of the matrix; And (c) an air electrode inserted into the other side groove of the matrix or coupled to the other side of the matrix.

The matrix is a kind of separation membrane that separates the air electrode and the fuel electrode from each other and enables the movement of the electrolyte. In the case of the outermost matrix, the matrix also functions as a sealing. Further, the matrix includes a molten electrolyte, and serves as a passage through which carbonate ions generated in the air electrode can move to the anode.

Therefore, in order to prevent contact between the air electrode and the fuel electrode, such a matrix is generally made larger than the size of the air electrode and the fuel electrode. However, as the size of the matrix and the sizes of the air electrode and the fuel electrode are different, a thin metal plate is arranged along the edge of the electrode to uniformize the thickness of the matrix and each electrode (air electrode and anode) .

However, in the present invention, a square groove is formed on one side or both sides of the matrix, and each electrode is disposed in the groove, so that the matrix plays a role of a thin metal. At this time, the matrix preferably has a length of 50 to 500 mm on one side, more preferably 80 to 130 mm, and most preferably 100 to 120 mm. In addition, a rectangular groove having a length of 40 to 490 mm, preferably 70 to 120 mm, and more preferably 90 to 110 mm may be formed on one side or both sides of the matrix (FIGS. 6 and 7). Therefore, the matrix is made larger by 5 to 20 mm in four directions than the electrodes. In addition, the matrix may include a _{Li-AlO 2, Li 2 CO} 3, Al, Al 2 O 3 Powder.

The thickness of the thickest portion of the matrix is 1.5 to 2.5 mm. The grooves of one side are formed to have a depth of 0.2 to 0.6 mm and the fuel electrode is inserted. The grooves of the other side are formed to have a depth of 0.2 to 1 mm The air electrode is inserted. It is preferable that each of the electrodes is formed to have the same thickness as the depth of the groove and inserted. If a groove is not formed on the other side of the matrix, the air electrode may be attached to the matrix and used.

The fuel electrode may include Ni-3Al or Ni-4Cr as an electrode for generating electrons by reaction between carbonate ions supplied from the air electrode and hydrogen supplied through internal reforming. The fuel electrode may be made to have the same size as the air electrode, but the thickness is preferably 0.2 to 0.6 mm, which is thinner than the air electrode. The fuel electrode may be made of a porous material so that fuel containing hydrogen can pass through the fuel electrode.

The cathode may be manufactured using nickel powder, electrolyte powder, or the like, which is an electrode for generating carbon dioxide by coupling the supplied carbon dioxide, oxygen and moving electrons. Further, the air electrode has a thickness of 0.2 to 1 mm and a length of 40 to 190 mm on one side, and can be manufactured by integrating with the grooves of the matrix. The air electrode may be made of a porous material so that a gas containing oxygen can pass through the porous electrode.

Further, the contact surface between the matrix and the fuel electrode or the contact surface between the matrix and the air electrode may have a concave-convex structure or a wave structure. As the contact surface between the matrix and each electrode is wider, the efficiency of the fuel cell is improved, so that the surface area can be increased by processing the contact surface between the matrix and each electrode. In the case of a conventional fuel cell, since each electrode is manufactured separately and then combined with the matrix, if there is a concavo-convex structure or a wave structure as described above, there may occur a gap at the time of coupling, and the movement of charges and ions may not be smooth . However, since the electrodes and the matrix are manufactured by integrating each electrode and the matrix in a continuous process, the electrodes and the matrix can be completely combined with each other while having a structure capable of widening the surface area. When the wave structure or the concavo-convex structure is formed on the contact surface between each electrode and the matrix, the contact area can be increased up to 4 times by the above structure, thereby increasing the cell size four times Lt; / RTI > Therefore, the fuel cell can be miniaturized as compared with the conventional fuel cell having the same performance.

In addition, various coating layers may be additionally formed on the contact surfaces of the electrodes and the matrix. When the nanoparticles are coated, the performance of the fuel cell can be improved due to the increase of the three-phase interface. When the catalyst (NiO, CeO _2, etc.) It is possible to prevent carbon caulking. In addition, when high-conductivity materials (Ag, ITO, gold, carbon nanotubes, etc.) are coated, the electrical conductivity can be increased. Such a coating layer can be used without limitation as long as it can uniformly coat the coating material, but it can preferably be coated by a spray method, a penetration method, or a screen printing method.

According to a second aspect of the present invention, there is provided a method of manufacturing an air electrode, comprising the steps of: (a) preparing an air electrode by supplying a mixed powder for an air electrode to a mold, or by injecting mixed powder for the air electrode into a mold; (b) preparing an air electrode-matrix combination body by binding a matrix for a matrix to the air electrode, supplying a mixed powder for a matrix and then applying pressure thereto, or injecting mixed powder for a matrix into a molding frame; (c) combining the fuel electrode mold with the air electrode-matrix combination body manufactured in the step (b), supplying the mixed powder for the fuel electrode, and then injecting the mixed powder for the fuel electrode into the mold, Producing; And (d) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly.

In the manufacturing method of the present invention, a mixture of the raw material powder and the organic binder of each electrode and matrix is manufactured through a dry process. Each powder is uniformly supplied to a shaping mold having a predetermined shape, and then pressed to form 4), each powder is directly injected into a molding die to be molded. The manufacturing method will be described in detail as follows.

(1) Production step of cathode

Ni powder, electrolytic powder, organic binder and lubricant are mixed for 10 to 60 minutes using a mixer to prepare a mixed powder for an air electrode, and then supplied to the air pole forming mold.

Examples of the organic binder include polyvinyl butyral (PVB), polyvinyl alcohol (PVA), or acrylic resin; (ii) natural wax, paraffin wax, polyethylene wax or carnauba wax as a lubricant (wax); And (iii) stearic acid or oleic acid as the dispersing agent.

The forming mold for the air electrode can be used regardless of the shape and shape of the air electrode so long as the shape of the air electrode can be formed. In addition, in the case of forming a wave structure or a concavo-convex structure on the surface of the air electrode, an air hole forming mold having a shape corresponding thereto may be used.

The mixed powder for the air electrode is supplied to the forming mold for the air electrode and then the mixture is heated at a pressure of 10 to 100 kg / cm 2, preferably 10 to 50 kg / cm 2, more preferably 15 to 25 kg / cm 2, The air electrode is formed by pressurization at a temperature of from -30 ° C to 130 ° C, more preferably from 90 ° C to 120 ° C for 10 seconds to 5 minutes, preferably 30 seconds to 2 minutes, more preferably 50 seconds to 70 seconds.

It is also possible to directly inject mixed powder for air electrode into the air hole forming mold to form an air electrode. In this case, a pressure of 10 to 100 kg / cm 2, preferably 10 to 50 kg / cm 2, more preferably 15 to 25 kg / cm 2 and a pressure of 60 to 200 ° C, preferably 90 to 170 ° C, And extraction can be taken out at a temperature of 60 ° C or lower.

(2) Manufacturing steps of the matrix

The matrix for a matrix is provided in the air electrode manufactured in the step (1), and then a matrix powder is supplied to prepare a matrix. The matrix mixed powder may be prepared by mixing Li-AlO ₂ , Li ₂ CO ₃ , Al, Al ₂ O ₃ powder, an organic binder and a lubricant using a mixer for 10 to 60 minutes.

Examples of the organic binder include polyvinyl butyral (PVB), polyvinyl alcohol (PVA), or acrylic resin; And (ii) natural wax, paraffin wax, polyethylene wax or carnauba wax as a lubricant (Wax); And (iii) stearic acid or oleic acid as the dispersing agent.

After the mixed powder for a matrix is supplied to a mold for a matrix, the mixture is pressurized or injected under the same conditions as the air electrode to form a matrix on the air electrode. In this case, when the matrix for forming the matrix is made larger than the air electrode, the matrix is formed into a shape covering the air electrode, and when it is made the same size as the air electrode, On one side of the matrix not contacting the air electrode, a groove having the same size as that of the air electrode is formed at a certain depth to form a space into which the fuel electrode is to be inserted. Also, in the case of forming the wave structure or the concavo-convex structure, the contact area between the fuel electrode and the fuel electrode may be increased, thereby improving the efficiency of the fuel cell.

(3) Production step of anode

The fuel electrode forming mold is provided in the air electrode-matrix composite produced in the step (2), and the fuel electrode mixture powder is supplied to prepare the fuel electrode. At this time, the fuel powder mixture may be prepared by mixing Ni-3Al, Ni-4Cr, an organic binder and a lubricant using a mixer for 10 to 60 minutes.

Examples of the organic binder include polyvinyl butyral (PVB), polyvinyl alcohol (PVA), or acrylic resin; And (ii) natural wax, paraffin wax, polyethylene wax or carnauba wax as a lubricant (Wax); And (iii) stearic acid or oleic acid as the dispersing agent.

After the mixture powder for the anode is supplied to the anode mold, the anode is pressurized or injected under the same conditions as the cathode to form a fuel electrode on the matrix. In this case, since the anode mold is formed so that the anode can be inserted into the groove of the matrix, the anode is completely inserted into the groove of one side of the matrix, and even if the one surface of the matrix has a wave structure or a concavo- As shown in FIG.

According to a third aspect of the present invention, there is provided a method of manufacturing an air electrode, comprising the steps of: (a) preparing an air electrode by feeding a mixture powder for an air electrode into a mold, or by injecting mixed powder for the air electrode into a mold; (b) supplying a mixed powder for a matrix to a mold, and then pressurizing the mixture; or injecting a mixed powder for a matrix into a mold to produce a matrix; (c) preparing a fuel electrode by supplying mixed powder for fuel electrode to a mold and then injecting mixed powder for fuel electrode into a mold; (d) combining and integrating the formed air electrode, the matrix, and the fuel electrode; And (e) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly.

In addition to the manufacturing method according to the second aspect, it is also possible to manufacture the electrodes and the matrix, respectively, and then to manufacture them integrally (FIG. 5). At this time, the composition, pressurization or injection conditions of each electrode can be manufactured in the same manner as in the second embodiment, and the contact surfaces of the electrodes and the matrix can have a wave structure or a concavo-convex structure.

Hereinafter, the present invention will be described in more detail with reference to examples.

Example 1

(1) Manufacture of cathode

Ni powder, electrolytic powder, PVB and paraffin wax were fed to a mixer and mixed for 30 minutes to prepare a powder mixture for an air electrode.

The mixed powder for the air electrode was supplied to an air electrode forming mold having a size of 100 mm x 100 mm and then pressed at a pressure of 20 kg / cm 2 and a temperature of 100 캜 for 1 minute to form a plate having a thickness of 0.7 mm.

(2) Manufacture of matrix

A matrix for a matrix was provided in the air electrode manufactured in the step (1), and then a mixed powder for a matrix was supplied to prepare a matrix.

The matrix mixed powder was prepared by feeding Li-AlO ₂ , Li ₂ CO ₃ , Al, Al ₂ O ₃ Powder, PVB and paraffin wax to a mixer and mixing them for 30 minutes.

The mixed powder for a matrix was supplied to a mold for a matrix having a size of 110 mm x 110 mm, and then a matrix was formed by pressurizing the mixture at a pressure of 20 kg / cm 2 and a temperature of 100 ° C for 1 minute. Was formed. The matrix was pressed by molding so that the thickness of the groove portion was 0.6 mm and the thickness of the thick portion was 2.0 mm.

(3) Manufacture of anode

The fuel electrode mold was prepared in the air electrode-matrix composite prepared in the step (2), and then the fuel electrode mixture powder was supplied to prepare the fuel electrode.

The fuel powder mixture was prepared by feeding Ni-3Al, Ni-4Cr, PVB and paraffin wax into a mixer and mixing them for 30 minutes.

The mixed powder for an anode was supplied to a mold for a fuel electrode having a size of 100 mm x 100 mm and then pressed at a pressure of 20 kg / cm < 2 > and a temperature of 100 DEG C for 1 minute to form a fuel electrode. The total height of the fuel electrode was the same So as to be molded.

Example 2

The air electrode was manufactured in the same manner as in Example 1 except that a forming mold having a wavy shape at the top was used and the inside of the groove was formed to have a wave structure in the production of the matrix.

Example 3

The procedure of Example 1 was repeated except that a mold having a concavo-convex shape was used for the manufacture of the cathode, and the inside of the groove was formed so as to have a concavo-convex structure in the production of the matrix.

Comparative Example 1

A cathode, a matrix, and a fuel electrode were prepared in the same manner as in the conventional method, respectively, and then combined to prepare a fuel cell. The raw materials used in each production, the pressurizing conditions, and the sizes of the electrodes were performed in the same manner as in Example 1.

Experimental Example

The initial current density and voltage were measured using the fuel cell manufactured in each of the examples and the comparative examples, and the voltage change was measured after 5000 hours of operation to test the durability. The experimental results are shown in Table 1 below.

Initial current density
(mA / cm 2) Initial voltage
(V) Voltage change
(? V) Measuring conditions Example 1 150 0.83 0.2 Current density = 150 mA / cm ² (maintenance)
Fuel utilization rate = 0.4 to 0.72
Operating temperature = 620 ^o C Example 2 150 0.84 0.1 Example 3 150 0.84 0.1 Comparative Example 1 150 0.82 0.2

As shown in Table 1, the molten carbonate fuel cell of Example 1 exhibited the same performance as Comparative Example 1 manufactured by the conventional method, even though the thin metal plate was not used. In Examples 2 and 3 which were processed into the structure or the concavo-convex structure, the initial voltage was increased. The durability was also found to be equal or higher than that of Comparative Example 1, which was produced by conventional methods.

While the present invention has been particularly shown and described with reference to specific embodiments thereof, those skilled in the art will appreciate that such specific embodiments are merely preferred embodiments and that the scope of the present invention is not limited thereto will be. Accordingly, the actual scope of the present invention will be defined by the appended claims and their equivalents.

Claims (7)

(a) a matrix having grooves formed on one side or both sides thereof;
(b) a fuel electrode inserted in one side groove of the matrix; And
(c) an air electrode inserted in the other side groove of the matrix or coupled to the other side;
Wherein the molten carbonate fuel cell comprises: The method according to claim 1,
And a concave-convex structure or a wave structure is formed on a contact surface of the matrix and the fuel electrode or a contact surface of the matrix and the fuel electrode. The method according to claim 1,
Wherein the matrix is a square having a length of 50 to 500 mm on one side and a square groove having a length of 40 to 490 mm on one side or both sides of the matrix is formed. A method for manufacturing an integrated molten carbonate fuel cell according to claim 1, comprising the steps of:
(a) preparing an air electrode by supplying a mixed powder for an air electrode to a mold, and then injecting mixed powder for the air electrode into a mold;
(b) preparing an air electrode-matrix combination body by combining a matrix forming mold with the air electrode, supplying a mixed powder for a matrix, and then pressurizing or injecting mixed powder for a matrix into a molding frame;
(c) combining the fuel electrode mold with the air electrode-matrix combination body manufactured in the step (b), supplying the mixed powder for the fuel electrode and then pressurizing it, or injecting mixed powder for the fuel electrode into the mold, ; And
(d) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly. A method for manufacturing an integrated molten carbonate fuel cell according to claim 1, comprising the steps of:
(a) preparing an air electrode by supplying a mixed powder for an air electrode to a mold, and then injecting mixed powder for the air electrode into a mold;
(b) supplying a mixed powder for a matrix to a mold, and then pressurizing the mixture; or injecting a mixed powder for a matrix into a mold to produce a matrix;
(c) preparing a fuel electrode by supplying mixed powder for fuel electrode to a mold and then injecting mixed powder for fuel electrode into a mold;
(d) combining and integrating the formed air electrode, the matrix, and the fuel electrode; And
(e) fabricating a molten carbonate fuel cell using the cathode-matrix-anode assembly. The method according to claim 4 or 5,
The mixed powder for an air electrode, the powder for a matrix or the mixed powder for a fuel electrode
(i) polyvinyl butyral (PVB), polyvinyl alcohol (PVA) or an acrylic resin as an organic binder; And
(ii) natural wax, paraffin wax, polyethylenetaline wax or carnauba wax as a lubricant;
(iii) Steric Acid or Oleic Acid as a dispersing agent;
Wherein the molten carbonate fuel cell comprises a plurality of molten carbonate fuel cells. The method according to claim 4 or 5,
The step (a), the step (b) or the step (c) may be carried out at a pressure of 10 to 100 kg / cm 2 and at a temperature of 60 to 150 ° C. for 10 seconds to 5 minutes. / Cm < 2 > and a temperature of 60 to 200 DEG C, and the take-out is taken out at a temperature of 60 DEG C or less.

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