KR100578557B1 - Manufacturing mathod of solid oxide fuel cell - Google Patents

Abstract

The present invention relates to a method for manufacturing a solid oxide fuel cell, and more particularly, to a method for manufacturing a solid oxide fuel cell that enables mass production of unit cells constituting a fuel cell to improve productivity of the fuel cell. It is about.

To this end, in the fuel cell manufacturing method prepared by sintering the cathode layer and the anode layer on both surfaces of the electrolyte layer formed by sintering through drying and annealing, the electrolyte layer is coated, divided and sintered after supplying the electrolyte slurry. Electrolyte layer manufacturing process for forming a, cathode electrode manufacturing process for coating the supplied cathode slurry on one surface of the electrolyte layer and then sintered to form cathode layer, and coating the supplied anode slurry on the other surface of the electrolyte layer and then sintered Characterized in that the anode layer manufacturing process for forming the anode layer.

According to the above configuration, since each slurry can be automatically and uniformly distributed and coated, there is an effect of improving the productivity of the fuel cell, and the thickness of each coating layer can be formed uniformly, so that there is no sintering defect. In addition, there is an effect that can produce a fuel cell having a stable and excellent electrical properties.

Fuel cell, unit cell, electrolyte, air electrode, fuel electrode

Description

Manufacturing method of solid oxide fuel cell

1 is a block diagram showing a procedure for manufacturing a fuel cell according to the present invention.

2 is a schematic diagram showing a manufacturing process of a fuel cell according to the present invention;

Figure 3a, 3b, 3c is a partial cutaway front cross-sectional view showing a process of forming an electrode film on the electrolyte layer according to the present invention.

* Description of Major Symbols in Drawings *

10-supply line 20-coater roller

30-Dryer 35-Cutter

40-Annealing Furnace 50-Transfer Tray

P1: Electrolyte layer manufacturing process P2: Air electrode layer manufacturing process

P3: anode layer manufacturing process CL: unit cell

E: electrolyte layer Es: electrolyte slurry

A: cathode layer As: cathode slurry

C: anode layer Cs: anode slurry

The present invention relates to a method for manufacturing a solid oxide fuel cell, and more particularly, to a method for manufacturing a solid oxide fuel cell that enables mass production of unit cells constituting a fuel cell to improve productivity of the fuel cell. It is about.

In general, a fuel cell is a type of power generation device that generates an electric current by using an oxidation / reduction reaction, and is a battery reaction caused by a continuous supply of reactants from outside. (Continued) to be removed continuously to obtain a current.

Today, advanced countries have been making efforts to develop alternative energy sources since the oil shock of the 1970s, and have developed fuel cells that can be generated using alternative energy such as methanol, ethanol and natural gas in addition to petroleum energy. .

Such a fuel cell not only serves as a next-generation power source, but also the system efficiency of the power source is more than 50% (efficiency of the existing internal combustion engine is less than 25%), and due to the characteristics that emit harmful gases such as NOx, SOx to less than 1% It is a clean, high efficiency power generation system that can drastically reduce air pollution and pollution caused by the use of existing petroleum energy.

As such, there are many fuel cells with high power generation potential, including the use of fossil fuels such as methane and natural gas in addition to hydrogen, and the use of liquid fuels such as methanol (methyl alcohol) and hydrazine. The temperature below about 300 degreeC is classified into a low temperature type, and the higher temperature is classified into a high temperature type.

In addition, a high-temperature molten carbonate fuel cell having improved power generation efficiency or a noble metal catalyst is used as a second generation fuel cell, and a solid oxide fuel cell that generates power with higher efficiency is a third generation fuel. It is classified as a battery.

Among these, in particular, the characteristics of solid oxide fuel cells are briefly described, because they operate at the highest temperature (700-1000 ° C) of existing fuel cells, and are simpler than other fuel cells because all components are solid. You can count. In addition, there is no problem of loss, replenishment and corrosion of electrolyte, no need for precious metal catalyst, easy fuel supply through direct internal reforming, and high temperature exhaust gas, which enables thermal combined cycle power generation using waste heat. .

The solid oxide fuel cell having the above characteristics is composed of an oxygen ion conductive electrolyte, a cathode and an anode disposed on both sides thereof.

In the following description, first, the electrolyte is composed of a material having high oxide ion conductivity and no electron conductivity and gas permeability. The cathode is a stable material in an oxide atmosphere and a material having high electron conductivity and air permeability. A stable material having excellent electron conductivity and breathability is used.

Referring to the approximate operating principle of the solid oxide fuel cell, in the cathode, the oxygen ions generated by the oxygen reduction reaction move to the anode through the electrolyte and react with hydrogen supplied to the anode to generate water. At this time, since electrons are generated at the anode and electrons are consumed at the cathode, electricity flows when the two electrodes are connected to each other.

On the other hand, the conventional method for manufacturing a unit cell of a solid oxide fuel cell for generating electricity as described above, although not shown in the drawings, the sintering method, vapor deposition method, plasma spray method, etc. after screen printing (Screen printing) There are many ways.

However, the methods listed above have many problems in terms of manufacturing and realizing fuel cells. First, after screen printing, the sintering method is essentially continuous by operations such as screen attachment, coating, and screen desorption when slurry coating is performed. Since it was impossible to work, it was difficult to secure the same coating quality, and there was a problem that cracks such as turtles could occur due to excessive shrinkage in the drying step or annealing step.

Moreover, the deposition method includes CVD, PVD, ESD, etc., but in general, since the deposition rate is slow and requires expensive equipment, the production cost and manufacturing cost are increased, thereby lowering the price competitiveness of the product. In addition, the thermal spray coating method does not apply to a product requiring electrical properties because of the large number of defects such as splat interface, cosmetic melting powder, crack, etc. due to the property of melting or coating only the surface or part of the metal powder.

The present invention has been made to solve the above-mentioned problems, the solid oxide fuel to improve the productivity of the fuel cell is possible to mass production of the unit cell because the entire process of forming the electrode in the electrolyte is made automatically It is to provide a method for manufacturing a battery.

Another object of the present invention is that it is possible to apply and coat each slurry in a certain amount, so that the thickness of the coating layer constituting the electrolyte and the electrode can be sintered to be uniform, respectively, to prevent sintering defects such as cracks and to provide excellent electrical properties. The present invention provides a method for manufacturing a solid oxide fuel cell.

The configuration of the present invention for achieving the above object is, in the manufacturing method of the fuel cell produced by sintering the cathode layer and the anode layer on both sides of the electrolyte layer formed by sintering through the drying and annealing step, the supplied electrolyte An electrolyte layer manufacturing process of coating and then sintering a slurry to form an electrolyte layer, a cathode layer manufacturing process of coating and then sintering the supplied cathode slurry on one surface of the electrolyte layer to form an anode layer, and the supplied anode slurry. After coating the other surface of the electrolyte layer and sintered to form a fuel electrode layer is characterized in that made of a process.

Here, the electrolyte layer manufacturing process is a step of supplying a predetermined amount of electrolyte slurry through a supply pipe installed in the front, coating the electrolyte slurry evenly by a coater roller installed behind the supply pipe, and the rear of the coater roller Drying the electrolyte slurry by a dryer provided, dividing the electrolyte slurry dried by a cutter installed at the rear of the dryer at a predetermined interval, and annealing the electrolyte slurry by an annealing furnace installed at the rear of the cutter. It is characterized by consisting of steps.

In addition, the cathode layer manufacturing process includes supplying a predetermined amount of cathode slurry through a supply pipe installed at the front, evenly distributing the electrolyte slurry by a coater roller installed at the rear of the supply pipe, and at the rear of the coater roller. And drying the cathode slurry in an installed dryer, and annealing the cathode slurry by an annealing furnace installed behind the dryer.

In addition, the anode layer manufacturing process includes supplying a predetermined amount of anode slurry through a supply pipe provided at the front, and evenly distributing the anode slurry by a coater roller installed at the rear of the supply pipe, and at the rear of the coater roller. And drying the anode slurry in an installed dryer, and annealing the anode slurry by an annealing furnace installed behind the dryer.

That is, through the supply pipe and coater roller, each corresponding slurry can be evenly distributed and coated automatically and uniformly, thereby enabling mass production of unit cells to improve the productivity of the fuel cell, and thus the thickness of each coating layer. It is possible to form a sintered constantly and to prevent sintering defects, and to manufacture a fuel cell having stable and excellent electrical properties.

When described in detail with reference to the accompanying drawings a preferred embodiment of the present invention.

1 or 2 schematically illustrate the manufacturing process of the solid oxide fuel cell of the present invention, in the order of the electrolyte layer manufacturing process (P1), the cathode layer manufacturing process (P2), and the anode layer manufacturing process (P3). The unit cell CL constituting the fuel cell is manufactured.

Hereinafter, each process will be described in detail. First, the electrolyte layer manufacturing process P1 is a process for sintering the electrolyte layer E. The process of supplying the electrolyte slurry Es again (S1) and the electrolyte slurry Es is performed. The coating step (S2) and the electrolyte slurry (Es) is divided into a step (S3) and the electrolyte slurry (Es) is divided into a step (S4) and the electrolyte slurry (Es) annealing processing (S5).

In order to explain, in step (S1) of supplying the electrolyte slurry (Es) by supplying the electrolyte slurry (Es) to the upper surface of the plate-shaped transfer table 50 is automatically transferred through the supply pipe 10 installed in the front, One supply pipe 10 is made of a structure for continuously supplying the electrolyte slurry (Es) by a predetermined amount automatically.

The electrolyte slurry (Es) is water or ethanol mixed with a mixture powder of 92% ZrO _₂ and 8% Y _₂ O _₃ , and mixed for several hours using a ball mill. In some cases, a mixture of 92% ZrO ₂ and 8% Y _₂ O _₃ mixed with acetone added with 1% to 5% binder may be used.

In the step of coating the electrolyte slurry (Es) (S2) using the coater roller 20 installed in the rear of the supply pipe 10 to the electrolyte slurry (Es) supplied in the step of supplying the electrolyte slurry (Es) (S1). It serves to distribute and coat evenly, by connecting a drive means such as a motor to the shaft of the coater roller 20 is installed so that the coater roller 20 rotates in a forward direction that conforms to the traveling direction of the feed table (50) do.

In the drying step (S3) of the electrolyte slurry (Es), the coated and distributed electrolyte slurry (Es) is dried at a high temperature by using a dryer (30) installed at the rear of the coater roller (20). It is dried for about 6 hours using. In addition, in the case of the electrolyte slurry (Es) to which acetone and a binder are added, a temperature of 500 ° C. or more is applied to the combustion process of the binder. The reason for applying such an appropriate drying temperature is to prevent sintering defects such as cracks in the electrolyte layer E when it is heated to a too high temperature during the drying process.

In the step S4 of dividing the electrolyte slurry Es, the dried electrolyte slurry Es is continuously divided at appropriate intervals by the cutter 35 installed at the rear of the dryer 30. Only the electrolyte slurry Es formed on the feed table 50 is regularly divided.

In the step of annealing the electrolyte slurry (Es) (S5) is a process of sintering the divided electrolyte slurry (Es) through the annealing furnace 40 installed behind the cutter 35, by applying a temperature of approximately up to 1350 ℃ The electrolyte layer (E) is sintered by going through a process for about 2 hours. The sintered electrolyte layer (E) is formed so that the thickness of the average coating layer is 50 ~ 200㎛, and the sintered density of about 90% or more compared to the theoretical density. At this time, the annealing furnace 40 is installed in a structure that goes through the heating process, the heating maintenance process and the cooling process in order.

On the other hand, the cathode layer manufacturing process (P2) is to form the cathode layer (A) on one surface of the electrolytic layer (S) formed by sintering through the above process, and again supplying the cathode slurry (As) (S6) and the cathode It is divided into a step (S7) of coating the slurry (As), a step (S8) of drying the cathode slurry (As) and a step (S9) of annealing the cathode slurry (As).

Hereinafter, in the step of supplying the cathode slurry As (S5), the cathode slurry (As) is supplied to one surface of the sintered electrolyte layer E, and the supply of the electrolyte slurry (Es) is performed (S1). By the supply pipe (11) installed in the front such that) is made of a structure for continuously supplying the cathode slurry (As) by a predetermined amount automatically. At this time, the cathode slurry (As) is used a mixture of La _0.8 Sr _0.2 MnO ₃ mixed powder and water.

In step S7 of coating the cathode slurry As, the supplied cathode slurry As is coated on one surface of the electrolyte layer E by using a coater roller 21 installed at the rear of the supply pipe 11. The coater roller 21 serves to uniformly distribute and coat the cathode slurry As as the coater roller 20 used in the step of coating the electrolyte slurry (S2), and drive means such as a motor. To the shaft of the coater roller 21 is installed so that the coater roller 21 rotates in a forward direction that conforms to the conveying direction of the feed table 50.

In step S8 of drying the cathode slurry As, the coated cathode slurry As is dried at a high temperature by using a dryer 31 installed at the rear side of the coater roller 21, using hot air at about 120 ° C. Dried for about 2 hours. The reason for the application of the drying temperature is to prevent the sintering defect of the cathode layer (A) due to drying at a high temperature.

In the step (S9) of annealing the cathode slurry As (S9) is a process of forming a film on one surface of the electrolyte layer (E) by using the annealing furnace 41 installed behind the dryer 31 as a dry cathode cathode (As). The cathode layer (A) is sintered to form an annealing process at a temperature of up to 1100 ° C. for about 2 hours. As described above, the cathode layer A formed on one surface of the electrolyte layer E is formed so that the average coating layer has a thickness of 10 to 100 μm, and the sintered density of about 80% or more of the theoretical density is obtained. At this time, the annealing furnace 41 is installed in a structure that undergoes a heating process, a heating maintenance process and a cooling process in order as in the step S5 of annealing the electrolyte slurry Es.

On the other hand, the anode layer manufacturing process (P3) is to form the anode layer (C) on the other surface of the electrolyte layer (E) having the cathode layer (A) is formed through the above-described process, the step of supplying the anode slurry (Cs) again (S10) and the coating of the anode slurry (S) (S11), the drying of the anode slurry (Cs) (S12) and the annealing process of the anode slurry (Cs) are divided into (S13).

In the following description, in operation S10 of supplying the anode slurry Cs, the anode slurry Cs is supplied to the other surface of the sintered electrolyte layer E, and the cathode slurry As is supplied (S6). By the supply pipe 12 is installed in the front such that the anode slurry (Cs) is automatically made of a structure that repeatedly supplies a predetermined amount. The anode slurry (Cs) uses a mixture of Ni-8YSZ mixed powder and water.

In step S11 of coating the anode slurry Cs, the supplied anode slurry Cs is coated on the other surface of the electrolyte layer E by using a coater roller 22 installed behind the supply pipe 12. The coater roller 22 serves to uniformly and uniformly distribute and coat the anode slurry Cs, and thus, detailed description thereof will be omitted because the same process as the step (S7) of coating the cathode slurry (As).

In step S12 of drying the anode slurry Cs, the coated anode slurry Cs is dried at a high temperature by using a drier 32 installed at the rear of the coater roller 22, and at about 120 ° C. for 2 hours. It is about to dry. This drying step is the same process as the step (S8) of drying the cathode slurry As described above, so the detailed description thereof will be omitted.

In step S13 of annealing the anode slurry Cs, the dried anode slurry Cs is sintered to the other surface of the electrolyte layer E using an annealing furnace 42 installed at the rear of the dryer 32. The anode layer (C) is sintered to undergo an annealing process for about 2 hours at a temperature of ℃. The anode layer C sintered as described above obtains a coating layer having the same thickness as the cathode layer A and the sintered density, and the annealing furnace 42 is also the same as the step S9 of annealing the cathode slurry As described above. It will be installed as a structure.

Referring to the operation and effect of the present invention configured as described in detail as follows.

In order to manufacture the unit cell CL constituting the solid oxide fuel cell, an electrolyte layer E is formed, and a cathode layer A and an anode layer C are formed on both surfaces of the electrolyte layer E. The unit cell CL is used after being stacked by stacking from tens to hundreds of layers to generate an appropriate output.

3A, 3B, and 3C, the steps of manufacturing the unit cell CL are described in order. First, the transfer table 50 automatically transfers a predetermined amount of electrolyte slurry Es from the supply pipe 10. It is supplied to the upper surface and the electrolyte slurry (Es) is evenly distributed and coated by the coater roller 20 while gradually moving in accordance with the transfer of the transfer table (50). Thus coated electrolyte slurry (Es) is dried while passing through the dryer 30, the dried electrolyte slurry (Es) is divided into a plate having a predetermined length and width by the cutter 35, the divided electrolyte slurry ( Es) passes through the annealing furnace 40 and sinters the electrolyte layer E as shown in FIG. 3a.

The electrolyte layer (E) formed as described above is gradually moved in accordance with the transfer of the transfer table 50, and one surface of the electrolyte layer (E) supplies a certain amount of cathode slurry (As) through the supply pipe (11). do. In addition, the cathode slurry As is evenly distributed and coated on one surface of the electrolyte layer E by the coater roller 21, and the dryer 31 and the annealing furnace 41 are the same as the sintering process of the electrolyte layer E. FIG. While the heat treatment is performed through), the cathode layer A is sintered to one surface of the electrolyte layer E as shown in FIG. 3B.

As such, when the cathode layer A is formed on one surface of the electrolyte layer E, the cathode layer C is sintered and formed on the other surface of the electrolyte layer E as shown in FIG. 3C. Since the process of forming the film is the same as the film forming process of the above-described cathode layer (A) and its shape, the duplicated description will be omitted.

At this time, in order to form the anode layer Cs as described above, after the cathode layer A is sintered on one surface of the electrolyte layer E, the anode slurry Cs is automatically supplied to the other surface of the electrolyte layer E. It must be structured. Therefore, in order to satisfy such a structure, the transfer table 50 between the annealing furnace 41 for annealing the cathode slurry A and the supply pipe 12 for supplying the anode slurry is reversibly installed to provide an electrolyte layer E. ) Can be reversed.

As described above, each unit cell CL may be automatically manufactured through the above-described process, and the solid state fuel cell may be manufactured by stacking the unit cells CL.

Therefore, in the method of manufacturing a solid oxide fuel cell of the present invention, each process of preparing the electrolyte layer (E), the cathode layer (A), and the anode layer (C) and each of the steps constituting the process are automatically performed. As a result, it is possible to mass-produce the unit cell constituting the fuel cell, thereby increasing the fuel cell productivity and significantly reducing the production cost and manufacturing cost of the fuel cell, thereby reducing the product's price competitiveness. It can be increased.

Furthermore, in the method for manufacturing a solid oxide fuel cell of the present invention, each slurry forming the electrolyte layer (E), the cathode layer (A), and the anode layer (C) is supplied with a supply pipe (10) (11) (12) and a coater roller ( 20) (21) (22) can be distributed and coated in a certain amount so that the thickness of the coating layer constituting the electrolyte, the cathode, and the anode can be uniformly formed, and sintering defects such as cracks can be prevented. Therefore, it is possible to manufacture a fuel cell having excellent electrical properties.

On the other hand, the present invention has been described in detail only with respect to the specific examples described above it will be apparent to those skilled in the art that various modifications and variations are possible within the technical scope of the present invention, it is natural that such variations and modifications belong to the appended claims. .

As described above, in the present invention, since each manufacturing step included in the electrolyte layer manufacturing process, the cathode layer manufacturing process, and the anode layer manufacturing process is performed automatically, the mass production of unit cells constituting the fuel cell is possible. This has the effect of increasing the productivity of the product, thereby reducing the production cost and manufacturing cost of the fuel cell more drastically, thereby increasing the price competitiveness and reliability of the product.

Moreover, since it is possible to apply and coat each slurry used to manufacture the electrolyte layer, the cathode layer, and the anode layer in a predetermined amount by the supply pipe and the coater roller, the cathode layer formed on both sides of the electrolyte layer as well as the electrolyte layer and Since the thickness of the anode layer can be uniformly and thinly formed, it is possible to prevent sintering defects of the coating layer and to produce a fuel cell having good coating properties.

Claims (7)

delete An electrolyte layer manufacturing step of coating and dividing the supplied electrolyte slurry and sintering to form an electrolyte layer, a cathode layer manufacturing process of coating and sintering the supplied cathode slurry on one surface of the electrolyte layer to form a cathode layer, and In the method of manufacturing a solid oxide fuel cell through the anode layer manufacturing process of coating the anode slurry on the other surface of the electrolyte layer and then sintering to form the anode layer, The electrolyte layer manufacturing step (P1), Supplying a predetermined amount of electrolyte slurry (Es) through a supply pipe (10) installed at the front (S1); Coating the electrolyte slurry (Es) evenly by a coater roller (20) installed behind the supply pipe (10) (S2); Drying the electrolyte slurry (Es) by a dryer (30) installed behind the coater roller (20) (S3); Dividing the electrolyte slurry (Es) dried by a cutter (35) installed behind the dryer (30) at a predetermined interval (S4); And annealing the electrolyte slurry (Es) by an annealing furnace (40) provided at the rear of the cutter (35). The method of claim 2, wherein the cathode layer manufacturing step (P2), Supplying a predetermined amount of cathode slurry (As) through a supply pipe (11) installed in front (S6); Coating the cathode slurry (As) evenly by a coater roller (21) installed behind the supply pipe (11) (S7); Drying the cathode slurry (As) by a dryer (31) installed behind the coater roller (21); And annealing the cathode slurry (As) by an annealing furnace (41) provided at the rear of the dryer (31). The method of claim 2, wherein the anode layer manufacturing step (P3), Supplying a predetermined amount of anode slurry (Cs) through a supply pipe (12) installed in front (S10); Coating the anode slurry (Cs) evenly by a coater roller (22) installed behind the supply pipe (12) (S11); Drying the anode slurry (Cs) by a dryer (32) installed behind the coater roller (22); And annealing the fuel electrode slurry (Cs) by an annealing furnace (42) provided at the rear of the dryer (32). The method of claim 2, wherein the electrolyte layer (E) formed in the electrolyte layer manufacturing step (P1) has an average coating layer thickness of 50 to 200 µm. The method of manufacturing a solid oxide fuel cell according to claim 3, wherein the cathode layer (A) formed in the cathode layer manufacturing step (P2) has an average coating layer thickness of 10 to 100 µm. The method for manufacturing a solid oxide fuel cell according to claim 4, wherein the anode layer (C) formed in the anode layer manufacturing step (P3) has an average coating layer thickness of 10 to 100 µm.

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