KR102543307B1 - High-performance ysz electrolyte supported solid oxide fuel cell of ultrasonic spray method and method of manuafcturing the same - Google Patents

Abstract

A high-performance solid oxide fuel cell based on YSZ solid electrolyte manufactured by ultrasonic spray that can be manufactured in a thin and uniform thin film form without aggregation between particles by forming a buffer layer and a cathode layer using an ultrasonic spray method and a manufacturing method thereof Initiate.
A method for manufacturing a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spraying according to the present invention includes the steps of coating a solid electrolyte coating material on a substrate and sintering to form a solid electrolyte layer; coating an anode coating material on one surface of the solid electrolyte layer and forming an anode layer by sintering; Forming a buffer layer by ultrasonically spraying a buffer slurry material from an ultrasonic spray nozzle on the other surface of the solid electrolyte layer and performing heat treatment; and forming a cathode layer by ultrasonically spraying a cathode slurry material from an ultrasonic spray nozzle on the buffer layer and heat-treating the material.

Description

YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray and its manufacturing method

The present invention relates to a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying and a manufacturing method thereof, and more particularly, to a thin, thin layer without aggregation between particles by forming a buffer layer and a cathode layer using an ultrasonic spray method. It relates to a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spray that can be manufactured in a uniform thin film form and a manufacturing method thereof.

A fuel cell is a device that produces electricity by reacting fuel such as hydrogen or natural gas with oxygen, and is one of the major energy technologies of the future due to its high efficiency, non-pollution, and noise-free characteristics.

In particular, a solid oxide fuel cell (SOFC) uses a solid oxide as an electrolyte that allows oxygen ions to pass through, and as electrolyte materials, zirconia (ZrO ₂ )-based oxide, ceria (CeO ₂ )-based oxide, and lanthanum- Strontium-gadolinium-magnesium oxide (LSGM) and the like are used.

These electrolytes include yttria (Y ₂ O ₃ ), ceria (CeO ₂ ), scandia (Sc ₂ O ₃ ), gadolinium oxide (Gd ₂ O ₃ ), etc. for the purpose of improving thermal stability and ionic conductivity at high temperatures. Contains some stabilizers.

A unit cell of a solid oxide fuel cell (SOFC) has a solid electrolyte interposed therebetween, an air electrode is attached to one side, and an anode is attached to the other side. In general, a mixture of nickel oxide (NiO) and yttrium stabilized zirconia (YSZ) is used for the anode, and lanthanum-strontium-cobalt oxide (LSC), lanthanum-strontium-manganese oxide (LSM), and lanthanum-strontium- Cobalt-iron oxide (LSCF), barium-strontium-cobalt-iron oxide (BSCF), and the like are used.

Recently, lanthanum-strontium-cobalt-iron oxide (LSCF) or barium-strontium-cobalt-iron oxide (BSCF), which are known to have better electrochemical characteristics of fuel cells than lanthanum-strontium-manganese oxide (LSM) cathodes Air electrodes are widely used.

However, the lanthanum-strontium-cobalt-iron oxide (LSCF)-based or barium-strontium-cobalt-iron oxide (BSCF)-based cathode material has a characteristic of reacting with a zirconia (ZrO ₂ )-based electrolyte, so that the process of sintering the cathode and complex oxides with low ion conductivity, such as lanthanum zirconate (La ₂ Zr ₂ O ₇ ) or strontium zirconate (SrZrO ₃ ), are formed at the interface between the cathode and the electrolyte while the battery operates at a high temperature.

Formation of the above reaction compounds reduces the rate at which oxygen ions formed at the cathode diffuse through the electrolyte and react with hydrogen at the anode, thereby degrading the overall performance of the fuel cell and causing a difference in thermal expansion coefficient, thereby improving thermal and mechanical stability. cause a decrease

As a related prior literature, there is Korean Patent Publication No. 10-2019-0028340 (published on March 18, 2019), which describes a solid oxide fuel cell and a battery module including the same.

An object of the present invention is a YSZ solid electrolyte-based high-performance solid oxide fuel cell based on ultrasonic spray that can be manufactured in the form of a thin and uniform thin film without aggregation between particles by forming a buffer layer and a cathode layer using an ultrasonic spray method, and It is to provide the manufacturing method.

In order to achieve the above object, a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to an embodiment of the present invention includes a solid electrolyte layer; an anode layer formed on one surface of the solid electrolyte layer; a buffer layer formed on the other surface of the solid electrolyte layer; and a cathode layer formed on the buffer layer, wherein each of the buffer layer and the cathode layer is formed by ultrasonic spraying to have a porous structure and has a packing density of 85 vol% or more.

The solid electrolyte layer is formed to a thickness of 100 ~ 400㎛.

The buffer layer is formed of gadolinium-ytterbium-bismuth-cerium oxide (GYBC).

The buffer layer is formed to a thickness of 1 to 15 μm.

The cathode layer includes a cathode support layer disposed on the buffer layer and a cathode functional layer laminated on the cathode support layer.

Each of the cathode supporting layer and the cathode functional layer is composed of yttria stabilized zirconium oxide (YSZ), scandia stabilized zirconium oxide (ScSZ), samarium doped ceria (SDC), gadolinium doped ceria (GDC), lanthanum strontium manganese oxide (LSM), lanthanum strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF), Samarium Strontium Cobalt Oxide (SSC), barium strontium cobalt ferrite (BSCF) and lanthanum strontium gallium magnesium oxide (LSGM).

In order to achieve the above object, a method for manufacturing a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spraying according to an embodiment of the present invention includes the steps of coating a solid electrolyte coating material on a substrate and sintering to form a solid electrolyte layer. ; coating an anode coating material on one surface of the solid electrolyte layer and forming an anode layer by sintering; Forming a buffer layer by ultrasonically spraying a buffer slurry material from an ultrasonic spray nozzle on the other surface of the solid electrolyte layer and performing heat treatment; and forming a cathode layer by ultrasonically spraying a cathode slurry material from an ultrasonic spray nozzle on the buffer layer and heat-treating the material.

The solid electrolyte layer is formed to a thickness of 100 ~ 400㎛.

The buffer layer is preferably formed of gadolinium-ytterbium-bismuth-cerium oxide (GYBC).

When the buffer layer is formed, after the ultrasonic spray, heat treatment is performed for 1 to 3 hours under conditions of 1,250 to 1,350 ° C.

The buffer layer is preferably formed to a thickness of 1 to 15 μm.

When the cathode layer is formed, after the ultrasonic spraying, heat treatment is performed for 1 to 3 hours under conditions of 1,150 to 1,250 ° C.

Each of the buffer layer and the cathode layer is formed by an ultrasonic spray method to have a porous structure and has a packing density of 85 vol% or more.

The cathode layer includes a cathode support layer disposed on the buffer layer and a cathode functional layer laminated on the cathode support layer.

Each of the cathode supporting layer and the cathode functional layer is composed of yttria stabilized zirconium oxide (YSZ), scandia stabilized zirconium oxide (ScSZ), samarium doped ceria (SDC), gadolinium doped ceria (GDC), lanthanum strontium manganese oxide (LSM), lanthanum strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF), Samarium Strontium Cobalt Oxide (SSC), barium strontium cobalt ferrite (BSCF) and lanthanum strontium gallium magnesium oxide (LSGM).

In the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to the present invention and its manufacturing method, each of the buffer layer and the cathode layer is formed by ultrasonic spraying to have a porous structure and have a packing density of 85 vol% or more.

As such, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to the present invention and its manufacturing method are thin and thin on a substrate by using a non-contact ultrasonic spray method spraying from an ultrasonic spray nozzle spaced apart from the substrate. It is possible to coat in a uniform form, and it may be possible to secure a high packing density of 85 vol% or more when the coating is made without aggregation between the dispersed particles.

In addition, the YSZ solid electrolyte-based high-performance solid oxide fuel cell and its manufacturing method manufactured by ultrasonic spray according to the present invention can reduce the contact resistance with the solid electrolyte layer by using GYBC, which has higher ionic conductivity than YSZ, as a buffer layer. In addition, it is possible to improve the performance of the fuel cell due to the smooth oxygen transport due to the application of the buffer layer and the cathode layer formed of a porous structure formed by the ultrasonic spray method.

Therefore, in the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to the present invention and its manufacturing method, it is possible to manufacture a large-area high-performance fuel cell by forming a buffer layer and a cathode layer by ultrasonic spraying. Therefore, it is possible to improve production yield by reducing process cost and time.

In addition, in the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to the present invention and its manufacturing method, the buffer layer coated in a uniform form without aggregation between the particles dispersed by the ultrasonic spray nozzle prevents formation of a secondary phase. Since it serves as a barrier to suppress, it is possible to fundamentally prevent ion diffusion between the solid electrolyte layer and the cathode layer.

1 is a cross-sectional view showing a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention.
Figure 2 is a schematic diagram for explaining the operating principle of the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention.
Figure 3 is a process flow chart showing a method for manufacturing a high-performance solid oxide fuel cell based on YSZ solid electrolyte manufactured by ultrasonic spray according to an embodiment of the present invention.
Figure 4 is a schematic diagram for explaining an ultrasonic spray device.
5 is an optical image obtained by photographing a SOFC unit cell sample according to Example 1;
6 is a SEM photograph showing a cut surface of a SOFC unit cell sample according to Example 1;
7 is an enlarged SEM photograph of an interface between a buffer layer and a cathode of a SOFC unit cell sample according to Example 1;
8 is an enlarged SEM photograph of a cathode of a SOFC unit cell sample according to Example 1;
9 is a graph showing IV characteristics results for SOFC unit cell samples prepared according to Example 1;
10 is a graph showing impedance spectra measurement results for SOFC unit cell samples manufactured according to Example 1;

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, and only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numbers designate like elements throughout the specification.

Hereinafter, a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spray according to a preferred embodiment of the present invention and a manufacturing method thereof will be described in detail with reference to the accompanying drawings.

1 is a cross-sectional view showing a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to an embodiment of the present invention, and FIG. 2 is a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to an embodiment of the present invention. It is a schematic diagram to explain the operating principle of an oxide fuel cell.

1 and 2, the YSZ solid electrolyte-based high-performance solid oxide fuel cell 100 manufactured by ultrasonic spray according to an embodiment of the present invention includes a solid electrolyte layer 140, an anode layer 120 and a cathode layer ( 180). In addition, the YSZ solid electrolyte-based high-performance solid oxide fuel cell 100 manufactured by ultrasonic spray according to an embodiment of the present invention further includes a buffer layer 160 formed between the solid electrolyte layer 140 and the cathode layer 180 .

The solid electrolyte layer 140 is used as a substrate of the solid oxide fuel cell 100 . This solid electrolyte layer 140 should not be gas permeable, have no electronic conductivity, but should have high oxygen ion conductivity.

Materials used as the solid electrolyte layer 140 include at least one selected from yttria stabilized zirconium oxide (YSZ), lanthanum-strontium-gallium-magnesium oxide (LSGM), and ceria (CeO ₂ )-based oxides. Among them, it is preferable to use yttria stabilized zirconium oxide (YSZ).

In addition, the anode layer 120 is formed on one side of the solid electrolyte layer 140. As a material used for the anode layer 120, one or more selected from Ni-Fe, yttria stabilized zirconium oxide (YSZ), scandia stabilized zirconium oxide (ScSZ), NiO, and the like may be used.

In the anode layer 120, oxygen receives electrons to become oxygen ions and passes through the solid electrolyte layer 140, and in the cathode layer 180, oxygen ions emit electrons and react with hydrogen gas to form water vapor.

Here, the cathode layer 180 is formed on the other surface of the solid electrolyte layer 140 . The cathode layer 180 includes a cathode supporting layer 182 disposed on the buffer layer 160 and a cathode functional layer 184 stacked on the cathode supporting layer 182 .

At this time, each of the cathode supporting layer 182 and the cathode functional layer 184 is composed of yttria stabilized zirconium oxide (YSZ), scandia stabilized zirconium oxide (ScSZ), samarium doped ceria (SDC), gadolinium doped ceria (GDC), lanthanum strontium manganese Oxide (LSM), Lanthanum Strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF) ), samarium strontium cobalt oxide (SSC), barium strontium cobalt ferrite (BSCF), and lanthanum strontium gallium magnesium oxide (LSGM).

Here, each of the anode layer 120 and the cathode layer 180 is formed to a thickness of 1 to 20 μm, and the solid electrolyte layer 140 is preferably formed to a thickness of 100 to 400 μm.

The buffer layer 160 is formed on the other surface of the solid electrolyte layer 140 and is disposed between the solid electrolyte layer 140 and the cathode layer 180 . At this time, the buffer layer 160 serves to fundamentally prevent ion diffusion between the solid electrolyte layer 140 and the cathode layer 180 from occurring between the solid electrolyte layer 140 and the cathode layer 180 .

As the material of the buffer layer 160, it is preferable to use ceria-based oxide, and more preferably, lanthanum (La)-doped ceria (LDC), gadolinium (Gd)-doped ceria (GDC), or samarium (Sm) At least one selected from among doped ceria (SDC), yttrium (Y) doped ceria (YDC), gadolinium (Gd), ytterbium (Yb), and bismuth (Bi) doped ceria (GYBC), etc. Among them, gadolinium-ytterbium-bismuth-cerium oxide (GYBC) is preferably used. As such, when GYBC having higher ionic conductivity than YSZ is used as the buffer layer 160 , contact resistance with the solid electrolyte layer 140 can be greatly reduced.

At this time, the buffer layer 160 is preferably formed to a thickness of 1 to 15 μm, more preferably to a thickness of 2 to 5 μm. When the thickness of the buffer layer 160 is less than 1 μm, the thickness is too thin, and thus it may be difficult to properly play a barrier role for suppressing the formation of a secondary phase. Conversely, when the thickness of the buffer layer 160 exceeds 15 μm, the excessive thickness may act as a factor that increases resistance, which is not preferable.

The YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to the above-described embodiment of the present invention has a porous structure in which a buffer layer and a cathode layer are formed by ultrasonic spraying, respectively, and has a packing density of 85 vol% or more.

As such, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention is thin and uniform on a substrate by using a non-contact ultrasonic spray method spraying from an ultrasonic spray nozzle spaced apart from the substrate. It is possible to coat in one form, and it may be possible to secure a high packing density of 85 vol% or more when the coating is made without aggregation between the dispersed particles.

In addition, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention can reduce the contact resistance with the solid electrolyte layer by using GYBC, which has higher ion conductivity than YSZ, as a buffer layer. In addition, it is possible to improve the performance of the fuel cell due to the smooth oxygen transport due to the application of the buffer layer and the cathode layer formed of a porous structure formed by the ultrasonic spray method.

Therefore, since the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to the present invention can be manufactured in a large area by forming a buffer layer and a cathode layer by ultrasonic spraying, It is possible to improve production yield by reducing process cost and time.

In addition, in the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying according to an embodiment of the present invention, the buffer layer coated in a uniform form without aggregation between the particles dispersed by the ultrasonic spray nozzle suppresses the formation of a secondary phase Since it serves as a barrier to prevent the occurrence of ion diffusion between the solid electrolyte layer and the cathode layer, it is possible to fundamentally prevent it.

Hereinafter, a method for manufacturing a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spray according to an embodiment of the present invention will be described with reference to the accompanying drawings.

3 is a process flow chart showing a method for manufacturing a YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention, and FIG. 4 is a schematic diagram for explaining an ultrasonic spray device.

As shown in FIG. 3, the method for manufacturing a high-performance solid oxide fuel cell based on a YSZ solid electrolyte manufactured by ultrasonic spray according to an embodiment of the present invention includes a solid electrolyte layer forming step (S110), an anode layer forming step (S120), a buffer layer A forming step (S130) and a cathode layer forming step (S140) are included.

Formation of solid electrolyte layer

In the solid electrolyte layer forming step (S110), a solid electrolyte layer to be used as a substrate is formed. Such a solid electrolyte layer may be formed by coating a solid electrolyte coating material on a substrate and sintering it.

That is, the solid electrolyte layer may be formed by preparing a solid electrolyte material by a solid phase method or a press manufacturing method and sintering the solid electrolyte material at 1,400 to 1,600° C. for 4 to 8 hours. Accordingly, the solid electrolyte layer is formed to a thickness of 200 ~ 400㎛.

At this time, as the solid electrolyte material, at least one selected from yttria stabilized zirconium oxide (YSZ), lanthanum-strontium-gallium-magnesium oxide (LSGM), and ceria (CeO ₂ )-based oxide may be used. Among these, it is preferable to use yttria stabilized zirconium oxide (YSZ) as the solid electrolyte material.

Formation of anode layer

In the anode layer forming step (S120), an anode coating material is coated on one surface of the solid electrolyte layer and sintered to form an anode layer.

Here, the anode layer, like the solid electrolyte layer, may be formed by preparing an anode material by a solid phase method and a press manufacturing method, and sintering at 1,300 to 1,500 ° C. for 1 to 3 hours. Accordingly, the anode layer is formed to a thickness of 1 to 20 μm.

As the anode material, at least one selected from among Ni—Fe, yttria stabilized zirconium oxide (YSZ), scandia stabilized zirconium oxide (ScSZ), and NiO may be used.

Formation of buffer layer

3 and 4, in the buffer layer forming step (S130), the buffer slurry material is ultrasonically sprayed from the ultrasonic spray nozzle 230 of the ultrasonic spray device 200 on the other surface of the solid electrolyte layer and heat-treated to form a buffer layer do. Here, it is preferable to arrange the other surface of the solid electrolyte layer to face the ultrasonic spray nozzle 230.

Here, the ultrasonic spray device 200 includes a heating plate 210 for heating the substrate 110 to a set temperature, a power supply unit 220 for supplying power to the heating plate 210, and generating ultrasonic waves. It includes an ultrasonic generator 240 and an ultrasonic spray nozzle 230 for spraying the slurry material converted into a fine mist by mechanical vibration by ultrasonic waves generated from the ultrasonic generator 240 onto the substrate 110.

In this way, the ultrasonic spray device 200 of the present invention sprays the slurry material converted into mist from the ultrasonic spray nozzle 230 onto the substrate 110, and the heating plate 210 can be heated to a set temperature there will be

In addition, the ultrasonic spray device 200 supplies a syringe 250 for controlling the supply amount of the slurry material supplied to the ultrasonic spray nozzle 230 and a compressed carrier gas to the ultrasonic spray nozzle 230 to form the slurry material. A carrier gas supply unit 260 for pressurization and a temperature controller 270 for controlling the temperature of the heating plate 210 may be further included.

When forming the buffer layer using the above-described ultrasonic spray device 200, after ultrasonic spraying, heat treatment is preferably performed for 1 to 3 hours under conditions of 1,250 to 1,350 ° C. At the time of such ultrasonic spraying, the thickness can be adjusted by adjusting the spraying time, the spraying amount, the amount of carrier gas input, and the like. Accordingly, the buffer layer is formed to a thickness of 1 to 15 μm, more preferably to a thickness of 2 to 5 μm.

Here, the buffer slurry material may be a mixture of polyvinyl butyral, a dispersant, ethanol, isopropyl alcohol, and zirconia balls in ceria-based oxide as a raw material, but is not limited thereto.

Ceria-based oxides include lanthanum (La)-doped ceria (LDC), gadolinium (Gd)-doped ceria (GDC), samarium (Sm)-doped ceria (SDC), and yttrium (Y)-doped ceria ( YDC), gadolinium (Gd), ytterbium (Yb), and bismuth (Bi) doped ceria (GYBC), etc. may be used, and among them, gadolinium-ytterbium-bismuth-cerium oxide (GYBC) may be used. It is preferable to use As such, when GYBC having higher ion conductivity than YSZ is used as the buffer layer, contact resistance with the solid electrolyte layer can be greatly reduced.

As such, in the present invention, since the buffer layer is formed by the ultrasonic spray method using the ultrasonic spray device 200, it is possible to form a thin and uniform thickness, and precise adjustment can be made using various pattern methods.

In addition, the ultrasonic spray nozzle 230 of the present invention suppresses aggregation of particles through continuous ultrasonic treatment during the ultrasonic spray process. Accordingly, since fine particles in which the solvent and the particles are well dispersed are formed, a higher specific surface area is obtained when the particles are coated by ultrasonic spraying.

In particular, the ultrasonic spray method is a non-contact method of spraying from the substrate 110 and the ultrasonic spray nozzle 230 spaced apart. Therefore, when the ultrasonic spray method is used, it is possible to coat the buffer slurry material in a thin and uniform form even on the ultra-thin substrate 110, and a high packing density of 85 vol% or more is achieved without aggregation between the dispersed particles. be able to secure

Cathode layer formation

In the cathode layer forming step (S140), a cathode slurry material is ultrasonically sprayed from the ultrasonic spray nozzle 230 of the ultrasonic spray device 200 on the buffer layer and heat-treated to form a cathode layer.

Here, when forming the cathode layer, like the anode layer, after ultrasonic spraying, heat treatment is preferably performed at 1,150 to 1,250° C. for 1 to 3 hours. At the time of such ultrasonic spraying, the thickness can be adjusted by adjusting the spraying time, the spraying amount, the amount of carrier gas input, and the like. Accordingly, the cathode layer, like the anode layer, is formed to a thickness of 1 to 20 μm.

Here, the cathode slurry material is a mixture of yttria stabilized zirconium oxide (YSZ) and lanthanum strontium manganese oxide (LSM), which are raw materials, and polyvinyl butyral, a dispersant, ethanol, isopropyl alcohol, and zirconia balls. It may be used, but is not limited thereto.

Here, raw materials of the cathode slurry material include scandia stabilized zirconium oxide (ScSZ), samarium doped ceria (SDC), gadolinium doped ceria (GDC), in addition to yttria stabilized zirconium oxide (YSZ) and lanthanum strontium manganese oxide (LSM), Lanthanum Strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF), Samarium Strontium At least one selected from cobalt oxide (SSC), barium strontium cobalt ferrite (BSCF), and lanthanum strontium gallium magnesium oxide (LSGM) may be used.

Since this cathode layer, like the anode layer, is formed by the ultrasonic spray method using the ultrasonic spray device 200, it is possible to form the cathode layer with a thin and uniform thickness, and precise adjustment can be made using various pattern methods. .

In addition, the ultrasonic spray nozzle 230 of the present invention suppresses aggregation of particles through continuous ultrasonic treatment during the ultrasonic spray process. Accordingly, since fine particles in which the solvent and the particles are well dispersed are formed, a higher specific surface area is obtained when the particles are coated by ultrasonic spraying.

In particular, the ultrasonic spray method is a non-contact method spraying from the substrate 210 and the ultrasonic spray nozzle 230 spaced apart. Therefore, when using the ultrasonic spray method, it is possible to coat the cathode layer in a thin and uniform form on the buffer layer, and it is possible to secure a high packing density of 85 vol% or more by coating without aggregation between the dispersed particles. . Therefore, each of the aforementioned buffer layer and cathode layer is formed by ultrasonic spraying to have a porous structure and have a packing density of 85 vol% or more.

In the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray according to an embodiment of the present invention manufactured by the above processes (S110 to S140), each of the buffer layer and the cathode layer is formed by the ultrasonic spray method to have a porous structure. and has a packing density of 85 vol% or more.

As such, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by the ultrasonic spray manufactured by the method according to the embodiment of the present invention is described by using a non-contact ultrasonic spray method spraying from an ultrasonic spray nozzle spaced apart from the substrate. It is possible to coat in a thin and uniform form on the surface, and it may be possible to secure a high packing density of 85 vol% or more when the coating is made without aggregation between the dispersed particles.

In addition, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying manufactured by the method according to the embodiment of the present invention reduces contact resistance with the electrolyte layer by using GYBC, which has higher ionic conductivity than YSZ, as a buffer layer. In addition, the performance of the fuel cell can be improved due to the smooth oxygen transport of the buffer layer and the cathode layer formed of a porous structure formed by the ultrasonic spray method.

Therefore, the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying manufactured by the method according to the embodiment of the present invention is a large-area high-performance fuel cell by forming a buffer layer and a cathode layer by ultrasonic spraying. Since it can be possible to do this, it is possible to improve the production yield by reducing process cost and time.

In addition, in the YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spraying manufactured by the method according to the embodiment of the present invention, the buffer layer coated in a uniform form without aggregation between the particles dispersed by the ultrasonic spray nozzle is secondary. Since it serves as a barrier to suppress the formation of phases, it is possible to fundamentally prevent ion diffusion between the solid electrolyte layer and the cathode layer.

Example

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and cannot be construed as limiting the present invention by this in any sense.

Contents not described herein can be technically inferred by those skilled in the art, so descriptions thereof will be omitted.

1. SOFC unit cell sample preparation

Example 1

After pressing yttria stabilized zirconium oxide (YSZ) on the substrate, it was sintered at 1,500° C. for 5 hours to form a solid electrolyte layer having a thickness of 250 μm.

Next, screen printing was performed on one side of the solid electrolyte layer at a weight ratio of 70wt% NiO and 30wt% YSZ, and then sintered at 1,400° C. for 2 hours to form an anode layer having a thickness of 10 μm.

Next, after ultrasonically spraying the buffer slurry material from the ultrasonic spray nozzle on the other side of the solid electrolyte layer, it is heat-treated at 1,300 ° C for 2 hours to have a thickness of 3 μm made of GYBC (Gd _0.135 Yb _0.015 Bi _0.02 Ce _0.83 O _1.915 ) material. A buffer layer was formed.

Next, after ultrasonically spraying the cathode slurry material from the ultrasonic spray nozzle on the buffer layer, heat treatment at 1,200 ° C. for 2 hours to obtain CFM (LSM 50wt% and YSZ 50wt%) and CCC (LSM 70wt% and YSZ 30wt%) materials SOFC unit cell samples were prepared by forming cathode layers having a thickness of 15 μm, which were sequentially stacked.

Here, when ultrasonic spray coating, 0.045 g of polyvinyl butyral, 0.015 g of dispersant, 2.7 g of ethanol, 6.3 g of isopropyl alcohol and 1 mm of isopropyl alcohol are added to 1.5 g of each slurry raw material A zirconia ball with a diameter of 8 g was used.

Example 2

After ultrasonic spraying, the SOFC unit was subjected to heat treatment at 1,300 ° C for 2 hours in the same manner as in Example 1, except that a 5 μm-thick buffer layer made of GYBC (Gd _0.135 Yb _0.015 Bi _0.02 Ce _0.83 O _1.915 ) material was formed. Cell samples were prepared.

Example 3

After ultrasonic spraying, heat treatment was performed at 1,300 ° C for 2 hours to form a 10 μm-thick buffer layer made of GYBC (Gd _0.135 Yb _0.015 Bi _0.02 Ce _0.83 O _1.915 ) SOFC unit in the same manner as in Example 1. Cell samples were prepared.

Comparative Example 1

An SOFC unit cell sample was prepared in the same manner as in Example 1, except that the buffer layer was not formed.

2. Microstructure observation

5 is an optical image obtained by photographing a SOFC unit cell sample according to Example 1; At this time, FIG. 5 shows a photograph taken after each coating of the buffer layer and the cathode layer by the ultrasonic spray method. In addition, FIG. 6 is an SEM picture showing a cut surface of a SOFC unit cell sample according to Example 1, and FIG. 7 is an enlarged SEM picture showing an interface between a buffer layer and a cathode layer of an SOFC unit cell sample according to Example 1. , FIG. 8 is an enlarged SEM picture of the cathode layer of the SOFC unit cell sample according to Example 1.

As shown in FIGS. 5 to 8, the SOFC unit cell sample prepared according to Example 1 has a uniform thickness as the buffer layer and the cathode layer are formed by the ultrasonic spray method, and the coating is performed without aggregation between the dispersed particles. It can be confirmed that this was formed into a porous structure.

At this time, in the case of the SOFC unit cell sample prepared according to Example 1, it was confirmed that the interface between the electrolyte layer and the buffer layer was well-connected, which suggests that the buffer layer serves to reduce the contact resistance.

3. Electrical Characteristics Evaluation

Table 1 shows I-V characteristic results for SOFC unit cell samples prepared according to Examples 1 to 3 and Comparative Example 1. 9 is a graph showing I-V characteristic results for SOFC unit cell samples manufactured according to Example 1.

[Table 1]

As shown in Table 1 and FIG. 9, it can be confirmed that the SOFC unit cell samples prepared according to Examples 1 to 3 have both increased current density and power density compared to the SOFC unit cell sample prepared according to Comparative Example 1. can

At this time, as the thickness of the buffer layer increased, both the current density and the power density tended to increase. In particular, it can be seen that the SOPC unit cell sample manufactured according to Example 3 showed the greatest increase in current density and power density.

At this time, both current density and power density increased when the buffer layer was present, but showed a tendency to decrease as the thickness of the buffer layer increased. As the buffer layer became thicker, the internal resistance increased, resulting in a decrease in power density. In particular, it can be confirmed that the SOFC unit cell sample manufactured according to Example 1 showed the greatest increase in current density and power density.

4. Impedance performance evaluation

Table 2 shows the results of measuring the impedance performance of the SOFC unit cell samples manufactured according to Example 1. 10 is a graph showing impedance spectra measurement results for SOFC unit cell samples manufactured according to Example 1.

[Table 2]

As shown in Table 2 and FIG. 10, the ohmic resistance and polarization resistance values of the SOFC unit cell sample manufactured according to Example 1 are shown. At this time, in the case of the SOFC unit cell sample prepared according to Example 1, it was confirmed that the ohmic resistance and polarization resistance values tended to decrease as the temperature increased.

Here, GYBC, which is a buffer layer, has higher ionic conductivity than YSZ, and its porous structure plays a role in facilitating oxygen transport, which is shown to increase performance.

As can be seen based on the above experimental results, when the buffer layer GYBC is formed by the ultrasonic spray method, it is judged to be helpful in improving the performance of the SOFC cell by suppressing the formation of a secondary phase.

Although the above has been described based on the embodiments of the present invention, various changes or modifications may be made at the level of a technician having ordinary knowledge in the technical field to which the present invention belongs. Such changes and modifications can be said to belong to the present invention as long as they do not deviate from the scope of the technical idea provided by the present invention. Therefore, the scope of the present invention will be determined by the claims described below.

100: solid oxide fuel cell 120: anode layer
140: solid electrolyte layer 160: buffer layer
180: cathode layer 182: cathode support layer
184: cathode functional layer
S110: solid electrolyte layer forming step
S120: Anode layer formation step
S130: Buffer layer formation step
S140: cathode layer forming step

Claims (15)

a solid electrolyte layer;
an anode layer formed on one surface of the solid electrolyte layer;
a buffer layer formed on the other surface of the solid electrolyte layer; and
A cathode layer formed on the buffer layer; includes,
Each of the buffer layer and the cathode layer is formed by an ultrasonic spray method to have a porous structure, and has a packing density of 85 vol% or more,
The buffer layer is formed by ultrasonic spraying and heat treatment of a buffer slurry material from an ultrasonic spray nozzle on the other surface of the solid electrolyte layer,
The buffer slurry material is a mixture of gadolinium-ytterbium-bismuth-cerium oxide (GYBC), polyvinyl butyral, a dispersant, ethanol, isopropyl alcohol, and zirconia balls,
The buffer layer is formed of gadolinium-ytterbium-bismuth-cerium oxide (GYBC), and the buffer layer is formed with a thickness of 2 to 5 μm. YSZ solid electrolyte-based high-performance solid oxide fuel cell made by ultrasonic spray.
According to claim 1,
The solid electrolyte layer is
YSZ solid electrolyte-based high-performance solid oxide fuel cell produced by ultrasonic spray, characterized in that formed to a thickness of 100 ~ 400㎛.
delete delete According to claim 1,
The cathode layer is
A cathode supporting layer disposed on the buffer layer;
YSZ solid electrolyte-based high-performance solid oxide fuel cell manufactured by ultrasonic spray, characterized in that it comprises a cathode functional layer laminated on the cathode support layer.
According to claim 5,
Each of the cathode supporting layer and the cathode functional layer is
Yttria Stabilized Zirconium Oxide (YSZ), Scandia Stabilized Zirconium Oxide (ScSZ), Samarium Doped Ceria (SDC), Gadolinium Doped Ceria (GDC), Lanthanum Strontium Manganese Oxide (LSM), Lanthanum Strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF), Samarium Strontium Cobalt Oxide (SSC), Barium Strontium Cobalt Ferrite ( BSCF) and lanthanum strontium gallium magnesium oxide (LSGM).
Forming a solid electrolyte layer by coating and sintering a solid electrolyte coating material on a substrate;
coating an anode coating material on one surface of the solid electrolyte layer and forming an anode layer by sintering;
Forming a buffer layer by ultrasonically spraying a buffer slurry material from an ultrasonic spray nozzle on the other surface of the solid electrolyte layer and performing heat treatment; and
Forming a cathode layer by ultrasonically spraying and heat-treating a cathode slurry material from an ultrasonic spray nozzle on the buffer layer; includes,
The buffer slurry material is a mixture of gadolinium-ytterbium-bismuth-cerium oxide (GYBC), polyvinyl butyral, a dispersant, ethanol, isopropyl alcohol, and zirconia balls,
The buffer layer is formed of gadolinium-ytterbium-bismuth-cerium oxide (GYBC), and the buffer layer is formed to a thickness of 2 to 5 μm. YSZ solid electrolyte-based high-performance solid oxide fuel cell manufacturing method.
According to claim 7,
The solid electrolyte layer is
YSZ solid electrolyte-based high-performance solid oxide fuel cell manufacturing method produced by ultrasonic spray, characterized in that formed to a thickness of 100 ~ 400㎛.
delete According to claim 7,
When forming the buffer layer,
After the ultrasonic spraying, the heat treatment is performed for 1 to 3 hours under conditions of 1,250 to 1,350 ° C. YSZ solid electrolyte-based high-performance solid oxide fuel cell manufacturing method produced by ultrasonic spray.
delete According to claim 7,
When forming the cathode layer,
After the ultrasonic spraying, the heat treatment is performed for 1 to 3 hours under conditions of 1,150 to 1,250 ° C. YSZ solid electrolyte-based high-performance solid oxide fuel cell manufacturing method produced by ultrasonic spray.
According to claim 7,
Each of the buffer layer and the cathode layer is
A method for manufacturing a high-performance solid oxide fuel cell based on a YSZ solid electrolyte produced by ultrasonic spray, characterized in that it has a porous structure formed by an ultrasonic spray method and has a packing density of 85 vol% or more.
According to claim 7,
The cathode layer is
A cathode supporting layer disposed on the buffer layer;
A method for manufacturing a high-performance solid oxide fuel cell based on YSZ solid electrolyte produced by ultrasonic spray, characterized in that it comprises a cathode functional layer laminated on the cathode support layer.
According to claim 14,
Each of the cathode supporting layer and the cathode functional layer is
Yttria Stabilized Zirconium Oxide (YSZ), Scandia Stabilized Zirconium Oxide (ScSZ), Samarium Doped Ceria (SDC), Gadolinium Doped Ceria (GDC), Lanthanum Strontium Manganese Oxide (LSM), Lanthanum Strontium Cobalt Ferrite (LSCF), Lanthanum Strontium Nickel Ferrite (LSNF), Lanthanum Calcium Nickel Ferrite (LCNF), Lanthanum Strontium Cobalt Oxide (LSC), Gadolinium Strontium Cobalt Oxide (GSC), Lanthanum Strontium Ferrite (LSF), Samarium Strontium Cobalt Oxide (SSC), Barium Strontium Cobalt Ferrite ( BSCF) and lanthanum strontium gallium magnesium oxide (LSGM).

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