KR102525346B1 - Anode for solid oxide fuel cell, solid oxide fuel cell and method of manufacuturing solid oxide fuel cell - Google Patents

Abstract

The fuel electrode of the solid oxide fuel cell includes a first sub fuel electrode layer formed on one side of an electrolyte of the solid oxide fuel cell - the first sub fuel electrode layer has BZY (Yttria doped Barium Zirconate, BaZr _x Y _y O _z ) as a core, Includes a plurality of first structures in which nickel (Ni) is formed on the surface of the core; a second sub fuel electrode layer formed on the first sub fuel electrode layer, wherein the second sub fuel electrode layer includes a plurality of second structures having BZY as a core and Ni formed on a surface of the core; and a third sub fuel electrode layer formed on the second sub fuel electrode layer, wherein the third sub fuel electrode layer includes a plurality of third structures having BZY as a core and Ni formed on a surface of the core. The weight percentage in the first sub-anode layer of the first structure is smaller than the weight percentage in the second sub-anode layer of the second structure, and the weight percentage in the second sub-anode layer of the second structure is the third sub-anode layer of the third structure. less than the weight percent within.

Description

Anode for solid oxide fuel cell, solid oxide fuel cell, and method for manufacturing solid oxide fuel cell

The present disclosure relates to a solid oxide fuel cell (SOFC) and a manufacturing method of the SOFC, SOFC having a fuel electrode containing BZY (Yttria doped Barium Zirconate, BaZr _x Y _y O _z ) and nickel (Ni) and a method for manufacturing SOFCs. The fuel electrode of the present disclosure includes functionally graded layers (FGLs) having a triple phase boundary (TPB) length.

The main function of the SOFC anode is to provide a site for the electrochemical oxidation reaction of fuel. The anode material must be stable in a reducing atmosphere of fuel and have sufficient electron conductivity and catalytic reactivity for reaction of fuel gas at an operating temperature. Since SOFCs operate at high temperatures of 600 °C to 1000 °C, thermal and chemical compatibility with other constituent materials must be maintained not only at room temperature and operating temperature, but also at higher temperatures, the manufacturing temperature of SOFCs. When hydrocarbon is used as fuel When Nickel-Yttria Stabilized Zirconia (Ni-YSZ) cermet is used as the anode, the anode is destroyed as the amount of carbon deposited increases by more than 12% by weight. Therefore, it is important to reduce the amount of deposition. When the Ni content of the Ni-YSZ anode is reduced, the electrical conductivity decreases, and when the content of YSZ is reduced, the ionic conductivity may decrease.

Korean Patent Registration No. 10-1111224 Korean Patent Registration No. 10-1602157 Korean Patent Registration No. 10-2035735 Korean Patent Publication No. 10-2010-0118256

The present disclosure provides an anode of an SOFC that reduces carbon deposition while maintaining the conductivity of Ni and YSZ in the anode of Ni—YSZ, a fuel cell having the same, and a manufacturing method thereof.

In one aspect of the present disclosure, the fuel electrode of the solid oxide fuel cell includes a first sub fuel electrode layer formed on one side of an electrolyte of the solid oxide fuel cell - the first sub fuel electrode layer is BZY (Yttria doped Barium Zirconate, BaZr) as a core. _x Y _y O _z ) and includes a plurality of first structures in which nickel (Ni) is formed on the surface of the core; a second sub fuel electrode layer formed on the first sub fuel electrode layer, wherein the second sub fuel electrode layer includes a plurality of second structures having BZY as a core and Ni formed on a surface of the core; and a third sub fuel electrode layer formed on the second sub fuel electrode layer, wherein the third sub fuel electrode layer includes a plurality of third structures having BZY as a core and Ni formed on a surface of the core. The weight percentage in the first sub-anode layer of the first structure is smaller than the weight percentage in the second sub-anode layer of the second structure, and the weight percentage in the second sub-anode layer of the second structure is the third sub-anode layer of the second structure. less than the weight percentage within the third sub-anode layer of the structure.

In one embodiment, the second sub anode layer and the third sub anode layer may further include Yttria Stabilized Zirconia (YSZ).

In one embodiment, the second sub fuel electrode layer and the third sub fuel electrode layer may further include nickel oxide (NiO).

In one aspect of the present disclosure, a solid oxide fuel cell includes an electrolyte, an air electrode formed on a first surface of the electrolyte; and a fuel electrode formed on a second surface of the electrolyte facing the first surface. The fuel electrode has a first sub fuel electrode layer formed on one side of the electrolyte of the solid oxide fuel cell, wherein the first sub fuel electrode layer includes a plurality of first structures having BZY as a core and Ni formed on the surface of the core; and A second sub fuel electrode layer formed on the first sub fuel electrode layer, wherein the second sub fuel electrode layer includes a plurality of second structures having BZY as a core and Ni formed on a surface of the core. A weight percentage within the first sub-anode layer of the first structure is smaller than a weight percentage within the second sub-anode layer of the second structure.

In one embodiment, a third sub fuel electrode layer formed on the second sub fuel electrode layer, wherein the third sub theatrical layer includes a plurality of third structures having BZY as a core and Ni formed on a surface of the core; and a weight percentage within the second sub-anode layer of the second structure may be less than a weight percentage within the third sub-anode layer of the third structure.

In one embodiment, the second sub fuel electrode layer and the third sub fuel electrode layer may further include YSZ.

In one embodiment, the second sub fuel electrode layer and the third sub fuel electrode layer may further include NiO.

In one aspect of the present disclosure, a method of manufacturing a solid oxide fuel cell includes preparing an electrolyte including YSZ; coating a first mixture slurry containing NiO, YSZ, and a first catalyst in which Ni is formed on a BZY core on a first surface of the electrolyte; Coating a second mixture slurry containing NiO, YSZ, and a second catalyst in which Ni is formed on a BZY core on the first mixture slurry, wherein the weight percentage of the second catalyst is greater than the weight percentage of the first catalyst. ; coating a third mixture slurry including a third catalyst in which Ni is formed on a BZY core on the second mixture slurry, wherein the weight percentage of the third catalyst is greater than the weight percentage of the second catalyst; Forming a first sub-anode layer, a second sub-anode layer, and a third sub-anode layer on the first surface of the electrolyte by sintering the electrolyte coated with the first, second, and third mixture slurries ; and forming an air electrode on a second surface of the electrolyte facing the first surface.

In one embodiment, the first to third mixture slurries further include a pore former, and the weight percentage of the pore former contained in the first and second mixture slurries is the third mixture slurry. may be less than the weight percent of the pore former.

As a catalyst for a hydrocarbon-based fuel cell, nano-sized Ni is coated on BZY ceramic powder having proton conduction and ion conduction, and this is fabricated into a Ni-YSZ-based fuel electrode functional gradient layer to enable practical use using hydrocarbon-based fuel. .

1 is an example of a unit cell of an SOFC according to an embodiment of the present disclosure.
2 is an example of a fuel electrode according to an embodiment of the present disclosure.
3A and 3B are conceptual views of a portion of an anode according to an embodiment of the present disclosure.
4 is a flowchart of a method of manufacturing an SOFC according to an embodiment of the present disclosure.
5 is a comparison graph of voltage and power density according to total area resistivity of a unit cell of a SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.
6 is a graph of voltage and power density of a unit cell of a SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.
7 is a graph showing a change in voltage over time between a unit cell of an SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.

Hereinafter, the present disclosure will be described in detail with reference to the drawings. In describing the present disclosure, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the gist of the present disclosure, a detailed description thereof will be omitted. In addition, the following examples may be modified in many different forms, and the scope of the technical spirit of the present disclosure is not limited to the following examples. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the spirit of the disclosure to those skilled in the art.

It should be understood that the techniques described in this disclosure are not intended to be limited to the specific embodiments, and include various modifications, equivalents, and/or alternatives of the embodiments of this disclosure.

In connection with the description of the drawings, like reference numerals may be used for like elements.

In the present disclosure, expressions such as “has,” “has,” “can have,” “includes,” or “can include” refer to corresponding features (eg, numerical values, functions, operations, or configurations of parts, etc.) element), and does not preclude the presence of additional features. In this disclosure, expressions such as “A or B,” “at least one of A and/and B,” or “one or more of A or/and B” may include all possible combinations of the items listed together. . For example, “A or B,” “at least one of A and B,” or “at least one of A or B” (1) includes at least one A, (2) includes at least one B, Or (3) may refer to all cases including at least one A and at least one B.

Expressions such as "first," "second," "first," or "second," used in the present disclosure may modify various elements regardless of order and/or importance, and may refer to one element as It is used only to distinguish it from other components and does not limit the corresponding components.

A component (e.g., a first component) is "(operatively or communicatively) coupled with/to" another component (e.g., a second component); When referred to as "connected to", it should be understood that the certain component may be directly connected to the other component or connected through another component (eg, a third component). On the other hand, when an element (eg, a first element) is referred to as being “directly connected” or “directly connected” to another element (eg, a second element), the element and the above It may be understood that other components (eg, a third component) do not exist between the other components.

The expression “configured to (or configured to)” as used in this disclosure means, depending on the situation, for example, “suitable for,” “having the capacity to.” ," "designed to," "adapted to," "made to," or "capable of." The term "configured (or set) to" may not necessarily mean only "specifically designed to" hardware. Instead, in some contexts, the phrase "device configured to" may mean that the device is "capable of" in conjunction with other devices or components. For example, the phrase “processor configured (or configured) to perform A, B, and C,” “module configured (or configured) to perform A, B, and C” refers to a dedicated processor (e.g., : embedded processor), or a general-purpose processor (eg, CPU or application processor) capable of performing corresponding operations by executing one or more software programs stored in a memory device.

Documents described as prior documents in this disclosure are incorporated in this disclosure by reference in their entirety.

1 is an example of a SOFC unit cell 100 according to an embodiment of the present disclosure. Referring to FIG. 1 , a SOFC unit cell 100 includes an air electrode 110 , an electrolyte 120 and an anode 130 . The air electrode 110 is also referred to as a cathode, and the fuel electrode 130 is referred to as an anode. In general, in the air electrode 110, oxygen adsorbed on the surface moves to the electrolyte 120 through dissociation/surface diffusion to obtain electrons and become oxygen ions, and the generated oxygen ions pass through the electrolyte 120 to the fuel electrode 130. move Oxygen ions diffused from the fuel electrode 130 and hydrogen react to emit electrons and simultaneously generate water and heat.

In one embodiment, the cathode 110 among the components of the SOFC unit cell 100 has high ion conductivity and electronic conductivity (50 (Ω cm) ^-1 or more), is stable in an oxidizing atmosphere, and is chemically compatible with other components. It can include porous (more than 30%) membranes with similar thermal expansion coefficients as well as no reaction and interdiffusion. For example, materials used as cathode materials include LaMnO ₃ based, LaCoO ₃ based, LSCF based, LSC based and the like. The material of the cathode may have a perovskite structure.

In one embodiment, the electrolyte 120 should be thermo-chemically stable in a wide temperature and oxidation-reduction atmosphere and have high ionic conductivity and low electronic conductivity. In addition, there is no gas leak by forming a thin and strong film. For example, as a material for the electrolyte 120, Yttria Stabilized Zirconia (YSZ) having a fluorite structure as an oxygen ion conductor may be used. In addition, as a material for the electrolyte 120, such as GDC (Ga doped Ceria 0.07 S/cm at 800 ° C) and SDC (Sm doped Ceria, 0.11 S / cm at 800 ° C) having high ionic conductivity, Ceria-based or LaGaO, Bi ₂ O ₃ systems can also be used. In addition, the ion conductor YSZ may be composited with transition metals such as electron conductors Co and Ni. Ni has excellent catalytic properties and electronic conductivity, and YSZ can be dispersed in Ni to control sintering behavior and create a three-phase interface. For optimal electrode characteristics, constant strength and porosity should be imparted, and uniform dispersion is required to secure long-term stability in an oxidation-reduction atmosphere.

In one embodiment, the fuel electrode 130 includes a functional graded layer. In one embodiment, the graded functional layer has a gradual change in composition or structure to have tailored properties. For example, in the functional gradient layer, a plurality of layers may be multi-layered, and each layer may have a different composition or structure. In the present disclosure, each of a plurality of layers included in the functional gradient layer may be referred to as a sub anode layer. In one embodiment of the present disclosure, the anode 130 may include a structure in which BZY (Yttria doped barium zirconate, BaZr _x Y _y O _z ) is used as a core and nickel (Ni) is deposited, coated, or formed on the surface of the core. can When Ni is deposited, coated, or formed on the BZY surface, oxygen and Ni may react to form NiO coating. Therefore, in the present disclosure, a structure in which Ni is deposited, coated, or formed on the surface of BZY may be referred to as Ni/BZY or NiO/BZY. For example, even if it is referred to as Ni/BZY in the present disclosure, it may be compatible with NiO/BZY, and even if it is referred to as NiO/BZY, it may be compatible with Ni/BZY. The fuel electrode 130 may further include NiO and YSZ in addition to Ni/BZY or NiO/BZY.

2 is an example of a fuel electrode 130 according to an embodiment of the present disclosure.

Referring to FIG. 2 , the fuel electrode 130 includes a first sub fuel electrode layer 132 , a second sub fuel electrode layer 134 , and a third sub fuel electrode layer 136 . For the sake of explanation, three sub-anode layers are exemplarily included, and the number of sub-anode layers is not limited to three. That is, the fuel electrode 130 may have two sub fuel electrode layers or four or more sub fuel electrode layers. In one embodiment, the first sub anode layer 132 may include NiO, YSZ, and NiO/BZY. The second sub anode layer 134 may include NiO, YSZ, and NiO/BZY. The third sub anode layer 136 may include YSZ and NiO/BZY. Alternatively, the third sub anode layer 136 may include NiO, YSZ, and NiO/BZY. Pores may be formed in the first sub fuel electrode layer 132 , the second sub fuel electrode layer 134 , and the third sub fuel electrode layer 136 . Porosity in the first sub anode layer 132 , the second sub anode layer 134 , and the third sub anode layer 136 may also be expressed as a weight percentage. In one embodiment, the porosity in the first sub anode layer 132 , the second sub anode layer 134 , and the third sub anode layer 136 may be about 35%-45%. That is, the porosity of the anode layer 130 may be about 35%-45%.

A first surface of the first sub anode layer 132 may contact the electrolyte 120 . One surface of the first sub anode layer 132 may directly contact the electrolyte 120 . A second surface of the first sub fuel electrode layer 132 facing the first surface of the first sub fuel electrode layer 132 may contact the first surface of the second sub fuel electrode layer 134 . A second surface of the second sub fuel electrode layer 134 facing the first surface of the second sub fuel electrode layer 134 may contact the first surface of the third sub fuel electrode layer 136 .

In one embodiment, the first sub fuel electrode layer 132 , the second sub fuel electrode layer 134 , and the third sub fuel electrode layer 136 may have different compositions. Weight percentages of NiO, YSZ, and NiO/BZY included in the first sub fuel electrode layer 132 , the second sub fuel electrode layer 134 , and the third sub fuel electrode layer 136 may be different from each other. A weight percentage of at least one of NiO, YSZ, and NiO/BZY included in the first sub fuel electrode layer 132, the second sub fuel electrode layer 134, and the third sub fuel electrode layer 136 may be different from each other. A weight percentage of at least one of NiO, YSZ, and NiO/BZY included in the first sub fuel electrode layer 132 , the second sub fuel electrode layer 134 , and the third sub fuel electrode layer 136 may be the same. A weight percentage of at least one of NiO, YSZ, and NiO/BZY included in at least two of the first sub fuel electrode layer 132, the second sub fuel electrode layer 134, and the third sub fuel electrode layer 136 may be the same. .

In one embodiment, the weight percentage of NiO/BZY in the first sub fuel electrode layer 132, the second sub fuel electrode layer 134, and the third sub fuel electrode layer 136 may increase as the distance from the electrolyte 120 increases. . That is, the weight percentage of NiO/BZY in the second sub fuel electrode layer 134 is greater than the weight percentage of NiO/BZY in the first sub fuel electrode layer 132. The weight percentage of NiO/BZY in the third sub anode layer 136 may be greater than that of NiO/BZY.

In one embodiment, the weight percentage of YSZ in the first sub-anode layer 132 , the second sub-anode layer 134 , and the third sub-anode layer 136 may decrease as the distance from the electrolyte 120 increases. That is, the weight percentage of YSZ of the second sub fuel electrode layer 134 is higher than the weight percentage of YSZ of the first sub fuel electrode layer 132, and the weight percentage of YSZ of the second sub fuel electrode layer 134 is greater than the weight percentage of YSZ of the third sub fuel electrode layer. The weight percentage of YSZ in (136) may be small.

In one embodiment, the NiO content of the sub anode layer furthest from the electrolyte 120 may be zero. In one embodiment, the YSZ content of the sub anode layer furthest from the electrolyte 120 may be zero. In one embodiment, the sub anode layer furthest from the electrolyte 120 may include only NiO/BZY.

In one embodiment, porosity of the first, second, and third sub-anode layers may be substantially the same or similar. Alternatively, porosity of the first, second and third sub anode layers may be different.

3A and 3B are conceptual views of a portion 300 of the fuel electrode 130 according to an embodiment of the present disclosure.

Referring to FIGS. 3A and 3B , a portion 300 of the fuel electrode 130 may be any one of the first sub fuel electrode layer 132 , the second sub fuel electrode layer 134 , and the third sub fuel electrode layer 136 . . Accordingly, a portion 300 of the fuel electrode 130 may be referred to as a sub fuel electrode layer 300 . The sub fuel electrode layer 300 may include NiO/BZY 310 and other components 320 . The other components 320 are shown blank without being separately shown. In one embodiment, other components 320 may include NiO, YSZ and pores.

In one embodiment, NiO/BZY (310) includes BZY (312) and NiO (314). NiO (314) may be formed on the BZY (312) surface. The BZY 312 may have a circular or polygonal column shape extending in one direction, for example, a pallet shape, a spherical shape, or an aspheric shape. That is, although the BZY 312 is conceptualized as a pallet shape in FIG. 3A and as a sphere in FIG. 3B, it may have various shapes different from these.

In an embodiment, BZY 312 may be a shape created when BZY is made into a powder. For example, the NiO/BZY 310 is coated with Ni on BZY structures in various shapes, such as pellets, spheres, non-spherical shapes, cylinders, and polygonal columns, manufactured by extrusion molding with BZY powder prepared by a solid phase method. can be a catalyst.

The inventors of the present disclosure prepared a Ni/BZY catalyst as follows. However, the present disclosure is not limited to this method.

BZY powder was prepared by the solid phase method. Specifically, BaCO ₃ (99.9%), ZrO ₂ (99.9%), Y ₂ O ₃ (99.9%) and acetone were mixed and homogenized, and dried at 110°C. The dried powder was heat treated in an air atmosphere at 1,150 ° C after attrition milling. The prepared BZY powder is a structure having a specific surface area of 10-20 m ² /g. Since the method of the prior patent (Korean Patent Registration No. 10-2035735) was used in the present disclosure, the prior patent may be referred to for more details.

In the temperature controlled chemical vapor deposition reaction, the precursor for Ni deposition is Ni(Cp) ₂ , and the amount of Ni coated on the surface can be controlled by injecting 5 wt% to 30 wt% based on the weight of the BZY carrier (BZY powder). . For the deposition of Ni, Ni vapor in the form of an organometallic compound sublimated at a temperature of 250 ° C reacted with oxygen in the air on the surface of the BZY carrier to form a NiO coating to prepare a NiO / BZY catalyst. NiO/BZY can be used as Ni/BZY through in-situ reduction.

4 is a flowchart of a method of manufacturing an SOFC according to an embodiment of the present disclosure.

Referring to FIG. 4, an electrolyte is prepared (S405). A first sub anode layer is formed on the prepared electrolyte (S410). In one embodiment, the first sub-anode layer may be formed by coating the first sub-anode layer slurry on the electrolyte using, for example, a screen printing method and drying the slurry. A second sub fuel electrode layer is formed in the dried first sub fuel electrode layer slurry (S415). In one embodiment, the second sub-anode layer may be formed by coating the second sub-anode layer slurry on the first sub-anode layer using a screen printing method and drying the slurry. A third sub fuel electrode layer is formed in the dried second sub fuel electrode layer slurry (S420). The third sub anode layer may be formed by coating the third sub anode layer slurry on the second sub anode layer using a screen printing method and drying the slurry. The dried first sub anode layer slurry, the dried second sub anode layer slurry, and the dried third sub anode layer slurry are sintered at a temperature between 1,000° C. and 1,300° C. for a set period of time to obtain a first sub anode layer and a second sub anode layer. An anode layer and a second sub anode layer may be formed. An air electrode is formed on the third sub fuel electrode layer (S425). A cathode may be formed by coating the cathode slurry on the third sub-anode layer and sintering at a temperature between 1,000° C. and 1,300° C. for a set time.

In one embodiment, it will be understood that the air electrode may be formed prior to the first to third fuel electrodes.

In order to measure and analyze the electrochemical characteristics of the SOFC unit cell to which the anode of the present disclosure is applied, the following unit cell was manufactured. After pressing the powder of YSZ, the electrolyte support was sintered at 1,400° C. for 5 hours to obtain a dense disc-shaped electrolyte support having a diameter of 18 mm and a thickness of 200 μm. The sub-anode layer slurry was prepared using a mixture of NiO, YSZ and the developed NiO/BZY as shown in Table 1 below, using organic binders ethyl cellulose and a-terpineol. Graphite 7-10 μm was used as the pore forming agent. It will be understood that materials other than NiO, YSZ, and NiO/BZY, which are the main materials of the anode, can be replaced with other materials.

NiO ratio (wt.%) YSZ ratio (wt.%) NiO/BZY ratio (wt.%) Pore former ratio (wt.%) First sub-anode layer slurry (NiO-YSZ-NiO/BZY) 55 30 10 5 Second sub-anode layer slurry (NiO-YSZ-NiO/BZY) 55 20 20 5 Third sub-anode layer slurry (NiO/BZY) 0 0 90 10

The first and second sub-anode layer slurries contain 5 wt.% of the pore former, and the third sub-anode layer slurry contains 10 wt.% of the pore-former. This is because when NiO is reduced and Ni is formed when the first and second sub-anode layers are formed using , pores may be formed at the site of oxygen.

Accordingly, although the ratio of the pore former included in the first and second sub fuel electrode layer slurries and the third sub fuel electrode layer slurry is different, the porosity of the first, second and third sub fuel electrode layers after sintering is substantially the same. or may be similar.

The first sub anode layer slurry was coated on the electrolyte support and dried for 30 minutes, the second sub anode layer slurry was coated and dried for 30 minutes, and the third sub anode layer slurry was coated and dried for 30 minutes. After that, it was sintered at 1,300°C for 2 hours. A cathode slurry was also prepared by mixing an organic binder, La _0.6 Sr _0.4 Co _0.2 Fe _0.8 O ₃ (LSCF), and a YSZ mixture in a weight ratio of 5:5. The electrode slurry was coated onto the electrolyte support by a screen printing method. Then, the button unit battery coated with the electrode was finally sintered at 1,150 °C for 2 hours. After sintering, it was confirmed that the thickness of the anode layer had a total thickness of 40 μm. Each sub anode layer had a thickness of about 10 to 15 μm and was well attached without peeling. NiO in the anode layer was reduced to Ni through in-situ reduction at 800 °C and used. The porosity of the anode layer is preferably about 35 to 45%. As a result of SEM Image Analysis, the porosity of the anode layer fired at 1,300 ° C according to the present invention was 37.2% after reduction at 800 ° C, confirming that it was suitable.

5 is a comparison graph of voltage and power density according to total area resistivity of a unit cell of a SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.

Referring to FIG. 5 , it can be seen that the result of measuring the change in voltage and power density according to the total area specific resistance (ASR) by impedance spectroscopy. 'FGLs' is a unit cell according to the present disclosure, and Ni-YSZ is a conventional unit cell. The total area resistivity (ASR) of the unit cell according to the present disclosure at 800° C. was about 0.2 Ωcm ² , and overall the total ASR of the unit cell according to the present disclosure was lower than that of the conventional Ni—YSZ unit cell depending on the operating temperature. This is because Ni percolation due to penetration of the Ni lattice inside the fuel electrode increases as total Ni increases due to the nano Ni contained in Ni/BZY. In addition, since BZY is a hybrid conductor having ion conduction as well as proton conduction, it can be substituted even if the amount of YSZ, an ion conductor, decreases. Accordingly, it can be seen that the unit cell according to the present disclosure can be applied to a commercialized fuel cell.

6 is a graph of voltage and power density of a unit cell of a SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.

Referring to FIG. 6 , at a CH ₄ fuel and an operating temperature of 800° C., the conventional Ni—YSZ battery exhibited a maximum power density of 0.38 W/cm ² . The unit cell according to the present disclosure exhibited a maximum power density of 0.44 W/cm ² . It was confirmed that the performance of the unit cell according to the present disclosure was about 20% higher than that of the existing Ni-YSZ, and this was due to the addition of Ni/BZY to the anode layer, which increased the catalytic activity for suppressing carbon deposition and reduced carbon deposition, so that the fuel could be supplied smoothly. It is thought that this is because it is supplied to the three-phase interface.

7 is a graph showing a change in voltage over time between a unit cell of an SOFC according to an embodiment of the present disclosure and a unit cell of a conventional SOFC.

Referring to FIG. 7, as a result of long-term operation of the conventional Ni-YSZ unit cell at 0.41 A/cm ² , CH ₄ fuel, and 800 ° C, it was confirmed that the voltage of the conventional Ni-YSZ electrode dropped due to carbon deposition from about 20 minutes did On the other hand, the unit cell according to the present disclosure showed little change in voltage and power density even after being operated for more than 50 hours at an operating temperature of 800° C. at 0.45 A/cm ² .

Accordingly, it can be seen that the unit cell according to the present disclosure improves the durability of the fuel cell by securing electrical conductivity and optimizing resistance to hydrocarbons.

As described above, although the embodiments have been described with limited drawings, those skilled in the art can apply various technical modifications and variations based on the above. For example, the described techniques may be performed in an order different from the method described, and/or components of the described system, structure, device, circuit, etc. may be combined or combined in a different form than the method described, or other components may be used. Or even if it is replaced or substituted by equivalents, appropriate results can be achieved.

Therefore, other implementations, other embodiments, and equivalents of the claims are within the scope of the following claims.

Claims (9)

delete delete delete delete delete delete delete As a method of manufacturing a solid oxide fuel cell,
Preparing an electrolyte containing YSZ;
coating a first mixture slurry containing NiO, YSZ, and a first catalyst in which Ni is formed on a BZY core on a first surface of the electrolyte;
Coating a second mixture slurry containing NiO, YSZ, and a second catalyst in which Ni is formed on a BZY core on the first mixture slurry, wherein the weight percentage of the second catalyst is greater than the weight percentage of the first catalyst. ;
coating a third mixture slurry including a third catalyst in which Ni is formed on a BZY core on the second mixture slurry, wherein the weight percentage of the third catalyst is greater than the weight percentage of the second catalyst;
Sintering the electrolyte coated with the first, second, and third mixture slurries to form a first sub-anode layer, a second sub-anode layer, and a third sub-anode layer on the first surface of the electrolyte step; and
Forming an air electrode on a second surface facing the first surface of the electrolyte,
A method of manufacturing a solid oxide fuel cell. According to claim 8,
The first to third mixture slurries further include a pore former, and the weight percentage of the pore former contained in the first and second mixture slurries is the weight of the pore former contained in the third mixture slurry A method of manufacturing a solid oxide fuel cell, less than a percent.

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