KR101341963B1 - Segment-in-series type sofc sub-module, preparation method thereof and segment-in-series type sofc module using the same - Google Patents

Abstract

The present invention relates to: a segment type solid oxide fuel cell sub-module capable of outputting high power and improving operation speed and thermal cycle resistance using a porous pipe type supporter with high gas permeability and excellent mechanical strength; a production method thereof; and a segment type solid oxide fuel cell module using the same.

Description

Segmented Solid Oxide Fuel Cell Submodule, Manufacturing Method Thereof and Segmented Solid Oxide Fuel Cell Module Using The Same

The present invention relates to a segmented solid oxide fuel cell submodule optimized by improving voltage-current performance, long-term stability, and thermal cycle characteristics, a method of manufacturing the same, and a segmented solid oxide fuel cell module using the same.

Solid Oxide Fuel Cell (SOFC) produces electricity by electrochemical reaction of fuel (H ₂ , CO) and air (oxygen) at high temperature of 600 ~ 1000 ℃ using solid ceramic as electrolyte. As a fuel cell, there is an advantage in generating power generation efficiency and excellent economic efficiency among the existing power generation technology.

Since the electrolyte and the electrode are in a solid state, the SOFC can be manufactured in various types of cells such as a plate type or a cylindrical type, and can be classified into an anode support type and an air cathode support type and an electrolyte support type according to a support of a fuel cell do.

Flat SOFCs have high power density, high productivity, and thin electrolyte, but require gas sealing using a separate sealant, and due to the use of metal connecting materials at high temperatures, electrode efficiency is reduced due to chromium volatilization. However, it has a disadvantage of lacking reliability due to low resistance to thermal cycles. Moreover, since flat panel SOFCs are not only difficult to manufacture large-area cells but also easy to manufacture large-capacity stacks, solving these problems becomes a key to practical use.

Cylindrical SOFCs are evaluated as SOFC designs closest to commercialization because they do not require gas sealing, have excellent mechanical strength, and have been tested for reliability in various test items. However, the cylindrical SOFC has a disadvantage of high internal resistance and low power density because of a long current path. In addition, since the voltage output from the module, which is a collection of cells, is low, the power conversion loss during operation is large, and as a result, there is a weakness in efficiency.

Currently, SOFC systems for power generation above 20 kW are mostly adopting stacks using cylindrical or improved cylindrical cells, and in the case of 20 kW or lower, flat cells are also adopted.

On the other hand, the segment-in-series type SOFC is one of the most advantageous and economical types of the improved cell type to compensate for the shortcomings of the conventional SOFC cell type for power generation. The cell is composed of nodes made of several cells. Since the segmented SOFC cell is a module in which unit cells are connected in series, it is possible to generate high efficiency with a high voltage and low current output, reduce the volume of the stack, and simplify the system. In addition, segmented SOFC cells can reduce stack manufacturing costs, apply low-cost wet coating processes that can be mass-produced, and minimize gas sealing problems by only gas sealing the edges of cylindrical cells. There is an advantage that the large area is easy through the increase in the length of the cylindrical cell support.

The present invention is a segmented solid oxide fuel cell submodule comprising a porous tubular support, a fuel electrode, an electrolyte layer, an air electrode, and a connecting member formed on the outer surface of the porous tubular support in Korea Patent Publication No. 2012-0034508, the porous tubular support is uniform And a paste prepared by kneading a mixture of powdered calcia stabilized zirconia (CSZ) and activated carbon powder, a binder, and distilled water, by extrusion, drying, heat treatment, and sintering. Starting a module.

Porous tubular supports used in segmented solid oxide fuel cell submodules must have mechanical and thermal stability and have a porous structure.

Segmented solid oxide fuel cell submodules generate power through electrochemical reactions in cells coated in series with a connecting material on the surface of the porous tubular support. For this reason, as the fuel permeation rate increases through the porous tubular support, high power generation is achieved, so the porosity increases. However, as the porosity increases, the mechanical properties are weakened. Therefore, the pore-forming agent must be determined and optimized in consideration of mechanical strength.

The present inventors have continued to improve the segmented solid oxide fuel cell disclosed in the prior art, as a result of using a porous tubular support with improved gas permeability and mechanical strength, the electrolyte layer having a compact structure of both the surface and the cross section It has been found that the present invention can improve voltage-current performance, long-term stability, and thermal cycle characteristics, thereby completing the present invention.

Accordingly, an object of the present invention is to provide a segmented solid oxide fuel cell submodule having improved voltage-current performance, long-term stability, and thermal cycle characteristics, a method of manufacturing the same, and a segmented solid oxide fuel cell module using the same.

In order to achieve the above object, the present invention is a segmented solid oxide fuel cell submodule comprising a porous tubular support, a fuel electrode, an electrolyte layer, an air electrode and a connecting member formed on the outer surface of the porous tubular support, the porous tubular support is uniform and powdered A paste prepared by kneading a mixture of oxidized 3 mol% yttria stabilized zirconia and activated carbon powder, a plasticizer, a lubricant, a binder, and distilled water is prepared by extrusion, drying, heat treatment, and sintering, and the electrolyte layer is 3 mol% It provides a segmented solid oxide fuel cell submodule, characterized in that it was manufactured using a slurry containing 9.5 ~ 10.5% by weight of yttria stabilized zirconia powder.

The present invention also provides a method for preparing a porous tubular support using a paste comprising a mixture of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon powder, a plasticizer, a lubricant, a binder, and distilled water (S1); Forming a fuel electrode on the porous tubular support (S2); 8 mol% yttria stabilized zirconia powder, a binder, a homogeneous agent, a dispersant, a plasticizer and a solvent are prepared on the anode to form an electrolyte layer using a paste (S3); Forming an air electrode on the electrolyte layer (S4); And forming a connection material for electrical connection (S5).

The present invention uses a porous tubular support that exhibits high gas permeability and excellent mechanical strength compared to the prior art, and forms an electrolyte layer having a dense structure on both the surface and the cross section, thereby improving voltage-current performance, long-term stability, and thermal cycle characteristics. A solid oxide fuel cell submodule, a method of manufacturing the same, and a segmented solid oxide fuel cell module using the same are provided.

1 (A) is a graph measuring current-voltage characteristics of a segment type solid oxide fuel cell submodule composed of two cells in Test Example 1 according to the present invention, and FIG. In Test Example 1, a graph measuring current-voltage characteristics of a segmented solid oxide fuel cell submodule including five cells is shown.
Figure 2 is a graph showing the results of measuring the long-term operation stability of the segment SOFC module consisting of five cells in Test Example 2 according to the present invention.
Figure 3 is a graph showing the results of measuring the thermal cycle of the segment SOFC module consisting of five cells in Test Example 2 according to the present invention.
4 is a photograph taken with a segment SOFC module consisting of 10 cells prepared in Test Example 3 according to the present invention.
FIG. 5 is a graph showing IVP performance measured for a segment SOFC module composed of 10 cells manufactured in Test Example 3 according to the present invention.
6 is a SEM photograph taken on the surface and the cross-section of the electrolyte layer prepared in Example 1 of the present invention.
7 is a SEM photograph taken on the surface and the cross-section of the electrolyte layer prepared in Comparative Example 1.

Hereinafter, a segmented solid oxide fuel cell submodule of the present invention, a manufacturing method thereof, and a segmented solid oxide fuel cell module using the same will be described in detail.

In addition, Korean Patent Publication No. 2012-0034508 of the present inventors is incorporated in its entirety by reference to the present invention.

The present invention is a segmented solid oxide fuel cell submodule comprising a porous tubular support, a fuel electrode, an electrolyte layer, an air electrode, and a connection member formed on the porous tubular support.

The porous tubular support is prepared by extrusion, drying, heat treatment and sintering of a paste prepared by mixing a mixture of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon powder, a plasticizer, a lubricant, a binder, and distilled water. It is characterized by using a thing.

In the segmented solid oxide fuel cell submodule, the porous tubular support serves as a flow path of fuel / reactant while forming a frame of a cell, and is composed of a material having no electrical conductivity because it connects two or more unit cells.

The porous tubular support used in the segmented solid oxide fuel cell submodule of the present invention is prepared using a paste containing a mixed powder of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon as a pore former. And high gas permeability and excellent mechanical strength as compared to porous tubular supports prepared using powdered calcia stabilized zirconia (CSZ) and activated carbon.

The segmented solid oxide fuel cell submodule according to the present invention is manufactured by sequentially forming a fuel electrode, an electrolyte layer, an air electrode, and a connecting material on the porous tubular support.

The anode is manufactured using a slurry prepared by mixing nickel oxide (NiO) powder, yttria stabilized zirconia (YSZ) powder, a binder, a homogeneous agent, a dispersant, a plasticizer and a solvent.

The electrolyte layer is formed by coating a slurry prepared by mixing yttria stabilized zirconia (YSZ) powder, a binder, a homogeneous agent, a dispersant, a plasticizer and a solvent on the anode.

The cathode is formed of a multilayer structure cathode in which an LSM-YSZ layer, an LSM layer, and an LSCF layer are sequentially formed.

The segmented solid oxide fuel cell submodule is preferably electrically connected by a connecting member after forming a plurality of unit cells consisting of a fuel electrode, an electrolyte layer, and an air electrode on a porous tubular support, for example, five or ten. See Test Examples 1-3.

The connecting member is formed in the segmented solid oxide fuel cell submodule to electrically connect the anode of the unit cell and the cathode of another unit cell.

 In one embodiment of the present invention, the connecting material may be formed using silver-glass paste, but may be used without limitation, materials commonly used in the art to which the present invention pertains.

Hereinafter, a method of manufacturing a segmented solid oxide fuel cell submodule of the present invention will be described.

First, a porous tubular support is prepared using a paste comprising a mixture of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon powder, a plasticizer, a lubricant, a binder and distilled water (S1).

In the present invention, 3 mol% yittria stabilized zirconia powder is used as a main raw material for preparing a porous tubular support, and active carbon powder is used as a pore forming agent, and 3 mol% or less is used. 5-15 parts by weight of activated carbon is mixed with 100 parts by weight of tria stabilized zirconia.

A mixture of 3 mol% yttria stabilized zirconia and activated carbon powder mixed according to the above-mentioned contents of use is prepared in a slurry state and homogenized by ball milling. At this time, ethanol is used as a solvent, and since ethanol is fast drying, the work can be performed quickly when dried in a dryer after ball milling. Ball milling is performed for two weeks using high purity zirconia balls, making it possible to make the mixture of 3 mol% yttria stabilized zirconia and activated carbon powder as uniform as possible.

Subsequently, the mixture of homogenized 3 mol% yttria stabilized zirconia and activated carbon powder is dried in a hot plate and then ground to powder.

Then, a paste is formed by kneading by adding a plasticizer, a lubricant, a binder, and distilled water to the powdered mixture.

The paste is based on 100 parts by weight of the mixed powder of the powdered 3 mol% yttria stabilized zirconia and activated carbon, 7 to 8 parts by weight of plasticizer, 6 to 7 parts by weight of lubricant, 17 to 18 parts by weight of binder, and 20 to 30 parts by weight of distilled water. It is prepared by mixing the parts.

As the binder, YB-131D, which is a comprehensive binder, may be used, and YB-131D is widely known as an organic binder including methyl cellulose and hydroxypropyl methyl cellulose, a plasticizer and a lubricant. The binder serves to bind the powdered mixture and to form pores with the activated carbon.

Next, the paste formed according to the above-described process is extruded into a porous tubular support using an extruder, and it is preferable to undergo a process of refrigeration so that the moisture of the paste is evenly distributed before extrusion.

Since the extruded porous tubular support is formed in a tubular shape, there is a fear that warpage or cracking may occur due to evaporation of the solvent during drying. Thus, in order to prevent this, a metal bar such as a steel bar is inserted into the tube of the porous tubular support and dried at room temperature while rolling with a rolling dryer.

Thereafter, the dried porous tubular support is subjected to a process of completely burning the binder and the activated carbon component added to the porous tubular support. That is, the temperature and the temperature are increased to 0.67 ℃ / minute to 200 ℃ slowly burning the remaining water and additives, and maintained for 3 to 5 hours at 200 ~ 300 ℃ to burn the binder slowly, and heated to 1 ℃ / minute to 600 ℃ After that, it is kept for 5 hours to completely burn the activated carbon.

Finally, the porous tubular support heat treated as described above is heated to 1.67 ° C./min to 1350-1450 ° C. to be calcined for 3 to 5 hours to complete the porous tubular support.

The porous tubular support manufactured according to the above-described method exhibits higher gas permeability and excellent compressive strength than the conventional porous tubular support, so that when used in a segmented solid oxide fuel cell submodule and a module using the same, high output power and start-up are possible. Segmented solid oxide fuel cell submodules with increased speed and thermal cycle resistance and modules using the same can be manufactured.

Next, a fuel electrode is formed on the porous tubular support (S2).

The anode is a nickel oxide (NiO) / yttria stabilized zirconia (YSZ) mixed powder 18 to 23% by weight, binder 3 to 7% by weight, homogeneous 0.5 to 3% by weight, dispersant 0.05 to 0.3% by weight, plasticizer 4 to 7% by weight % And 65 to 70 wt% of the solvent may be mixed to form a slurry, and then coated on a porous tubular support using a dip coating method or the like. Since the anode is preferably heat treated for about 1.5 to 4.5 hours at about 900 ~ 1100 ℃.

In one embodiment of the invention, the nickel oxide (NiO) / yttria stabilized zirconia (YSZ) mixed powder is prepared by mixing 66% by weight of nickel oxide (NiO) powder and 34% by weight of yttria stabilized zirconia (YSZ) powder. Can be.

In addition, the solvent may be a mixture of 36% by weight of toluene and 64% by weight of isopropyl alcohol.

Next, an electrolyte layer is formed on the fuel electrode (S3).

8 mol% yttria stabilized zirconia powder 9.5-10.5 wt%, 0.9-1.1 wt% binder, 0.19-0.21 wt% homogenizer, 0.022-00.024 wt% dispersant, 0.9-1.1 wt% plasticizer to form electrolyte layer on the anode % And 87 to 88% by weight of a solvent are mixed to prepare a slurry, and the prepared slurry is coated on a fuel electrode using a vacuum slurry coating method. Since the electrolyte layer is preferably heat-treated for 3 to 7 hours at about 1250 ~ 1450 ℃.

In the present invention, when the paste for forming the electrolyte layer on the anode includes less than 9.5 wt% of 8 mol% yttria stabilized zirconia powder, the electrolyte layer is thinly formed, thereby increasing the probability of occurrence of defects. In addition, there is a problem in that the electrolyte resistance is increased (the ion conductivity is lowered) because the manufacturing cost is increased and the electrolyte layer is formed to be thicker than 8 mol% yttria stabilized zirconia powder is included in excess of 10.5% by weight.

In one embodiment of the present invention, a mixture of 38% by weight of toluene and 62% by weight of isopropyl alcohol may be used as the solvent.

Next, an air electrode is formed on the electrolyte layer (S4).

In the present invention, the cathode may be a multilayer structure cathode in which an LSM-YSZ layer, an LSM layer, and an LSCF layer are sequentially formed on an electrolyte layer.

In order to coat the cathode of the multilayer structure as the cathode, Ls ₂ O ₃ , SrCO ₃ , Co (NO ₃ ) ₂ 6H ₂ O, Fe ₂ O ₃ , MnO ₂ raw powders were quantitatively determined by solid state reaction (Solid State Reaction). ) (La, Sr) MnO ₃ Powder, (La, Sr) (Co, Fe) O ₃ powder is prepared.

(La, Sr) MnO ₃ 18-23 wt% of yttria stabilized zirconia (YSZ) powder, 3-7 wt% of binder, 0.5-3 wt% of homogenizer, 0.05-0.3 wt% of dispersant, 4-7 wt% of plasticizer and 65-70 wt% of solvent To prepare a slurry to form the LSM-YSZ layer by mixing.

(La, Sr) MnO ₃ / Yttria stabilized zirconia (YSZ) powder mixture is (La, Sr) MnO ₃ One prepared by mixing 50% by weight of powder and 50% by weight of yttria stabilized zirconia (YSZ) may be used.

In the same manner, (La, Sr) MnO ₃ powder 18-23 wt%, binder 3-7 wt%, homogenizer 0.5-3 wt%, dispersant 0.05-0.3 wt%, plasticizer 4-7 wt% and solvent 65-70 wt% Mix% to make a slurry to form an LSM layer.

Similarly (La, Sr) (Co, Fe) O ₃ powder 18-23% by weight, binder 3-7% by weight, homogenizer 0.05-3% by weight, dispersant 0.05-0.3% by weight, plasticizer 4-7% by weight and solvent 65 -70 wt% is mixed to prepare a slurry for forming the LSCF layer.

In one embodiment of the present invention, a mixture of 36% by weight of toluene and 64% by weight of isopropyl alcohol may be used as the solvent used in the slurry for forming the air electrode.

After masking the remaining portions of the porous tubular support except for the portion where the cathode is to be formed, twice in sequence in the slurry for forming the LSM-YSZ layer, the slurry for forming the LSM layer, and the slurry for forming the LSCF layer- The immersion coating may be performed once or twice to form a multilayer structure cathode.

Finally, to form a connection for electrical communication of the segmented solid oxide fuel cell submodule (S5).

The segmented solid oxide fuel cell submodule according to the present invention has a structure in which unit cells including a connecting electrode, an electrolyte layer, and an air electrode are connected in series by a connecting material on a porous tubular support. That is, the connecting member electrically connects the anode of the unit cell and the cathode of the other unit cell in the segmented solid oxide fuel cell submodule to enable electrical communication between the unit cells.

In one embodiment of the present invention, the connecting material may be formed by coating a silver-glass paste.

The silver-glass paste may be prepared by mixing 53 to 57 wt% silver powder, 4 to 8 wt% glass powder, 3 to 6 wt% binder, and 31 to 35 wt% solvent.

The connecting material should be excellent in electrical conductivity, and the gas sealing property should be secured, and may exhibit excellent electrical conductivity by the silver powder included in the silver-glass paste, and may exhibit the gas sealing effect by the glass powder.

In the present invention, the binder used in the preparation of the slurry for forming the anode, the electrolyte layer, and the cathode may use BM1, BM2, PVB, etc., the homogeneous agent may use Triton X-100, and the dispersant may be a SN-dispersant. Dibutyl phthalate may be used, and the solvent may be a mixed solvent of toluene and isopropyl alcohol.

Methyl cellulose may be used as the binder used in the production of the silver-glass paste for forming the linking material, and α-terpinol may be used as the solvent.

The method of forming the anode, the electrolyte layer, the cathode and the connecting member on the porous tubular support prepared as described above according to the present invention is the same as that disclosed in Korean Patent Laid-Open No. 2012-0034508, which is incorporated herein by reference.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary meanings and should be construed in accordance with the technical meanings and concepts of the present invention.

The embodiments and drawings described in the present specification are preferred embodiments of the present invention and are not intended to represent all of the technical ideas of the present invention, so that various equivalents and modifications may be substituted for them at the time of application of the present invention.

Example  One

3 mol% yttria stabilized zirconia powder (3YSZ powder), the main raw material, was used as a pore-forming agent for preparing a porous tubular support, and activated carbon (Kuraray Chemacl Co., Janpan) powder was weighed at 15 parts by weight based on 100 parts by weight of 3YSZ powder. And mixed. After ethanol was added, the mixed powder was uniformly subjected to wet ball milling for 2 weeks using high purity zirconia balls, and then dried in a hot box at 80 ° C. for 24 hours. After drying, the mixture was ground using a sieve having a size of 100 and 200 µm to obtain a mixed powder in which the support powder and the pore-forming agent were uniformly mixed.

To the prepared mixed powder, an aqueous composite binder (YB-13D, SERANDER, .CO. Japan), a plasticizer, a lubricant, a solvent (distilled water) are added to the ingredients shown in Table 1, materials and contents thereof. To produce an extrusion paste. In the kneading process, first, the mixed powder and the water-based binder were mixed in a powder state for 30 minutes, and then a liquid solution mixed with a plasticizer, a lubricant, and distilled water was made and added uniformly. The 3YSZ supporter prepared a paste for extrusion to achieve a smooth extrusion by controlling the content of the distilled water at a ratio of 1: 1 by the ratio of the pore-forming agent and the distilled water. The prepared extrusion paste was refrigerated for 24 hours so that the solvent was evenly distributed, and then the extruded porous tubular support.

Then, NiO-YSZ powder (Fuelcellmaterials Co.), binders, dispersants, plasticizers, and solvents were mixed to prepare a slurry in which 20 wt% of NiO-YSZ powder was added to the anode, and then immersed on the surface of the plasticized support. The anode was coated by the method. In the anode coating, the pulling speed and the cutting speed were 0.8 and 0.2 cm / s, respectively, and the coating holding time was maintained for 10 seconds. The coated anode was peeled off after masking at room temperature for 60 minutes and heat-treated at 1000 ° C. for 3 hours. The electrolyte was prepared by using a vacuum slurry coating method to prepare a slurry in which 10 mol% of 8 mol.% YSZ powder (Tosoh Co.) was added in order to manufacture a thin film. One end of the cylindrical support was flattened with sand paper and covered with Teflon sheet, and the other end was connected to a vacuum pump. When the vacuum pump was operated to produce a vacuum pressure of 70 kPa or more, the support was placed in the electrolyte slurry and held for 30 seconds. After the electrolyte coating, the masking tape was removed, dried at room temperature for 60 minutes, and then heat-treated at 1400 ° C. for 5 hours. Three coating slurries were prepared in which LSM / YSZ, LSM and LSCF powder (Fuelcellmaterials Co.) were added at 20% by weight to coat the cathode having a multilayer structure of LSM / YSZ, LSM and LSCF. The prepared cathode slurry was dip-coated sequentially twice, once and twice in the order of LSM / YSZ, LSM and LSCF. Each coating was dried at room temperature for 30 minutes, and then coated in reverse direction in order to obtain a uniform coating layer. After the cathode coating, the masking was removed after drying at room temperature for 60 minutes, and heat treatment was performed at 1150 ° C. for 3 hours to prepare a segmented solid oxide fuel cell submodule.

Comparative Example  One

Segmented solid oxide fuel was carried out in the same manner as in Example 1 except that a slurry prepared by adding 3 mol% of 8 mol.% YSZ powder (Tosoh Co.) was prepared in order to manufacture the electrolyte layer into a thin film. Battery submodules were prepared.

Test Example  1: consisting of 2 and 5 cells Segment SOFC  Comparative performance evaluation of modules

According to Example 1, a segmented solid oxide fuel cell submodule consisting of two and five cells, respectively, was prepared, and coated on the surface of each porous support by silver-glass connector brush water coating for gas sealing and current collection. The completed Segment SOFC module attached a suscap connected to a sus tube using a cerama bond at both ends, and collected the anode and the cathode using silver-mesh and silver-wire to evaluate electrical characteristics. Performance evaluation was carried out with a segment SOFC module consisting of two and five cells, in which air was injected with hydrogen and oxidant humidified to 3% as fuel. Operating temperature was changed to 700, 750, 800 ℃, the current-voltage characteristics were measured using a DC electronic load and the results are shown in FIG.

Referring to FIG. 1, at 700, 750, and 800 ° C, the open circuit voltage (OCV) and the maximum power density are 1.59, 1.82, 1.9 V and 35, 68, 106 mW for a two-segment SOFC module. / cm ² (see FIG. 1A), and for a five-cell segment SOFC module, 5.1, 5.13, 5.15 V and 135, 223, 276 mW / cm ² (see FIG. 1B). As can be seen from the result, it was found that the OCV of the five-cell segment SOFC module is more stable and shows higher performance than the two-cell segment SOFC module. This result may be attributed to the increase in resistance due to electrolyte defects in the segment SOFC module consisting of two cells.

Test Example  2: consisting of 5 cells Segment SOFC  Module performance evaluation

Performance evaluation of the segment SOFC module consisting of five cells manufactured in Test Example 1 was performed. Performance evaluation was performed at the operating temperature of 650 ℃, and the voltage change was measured by applying a constant current of 0.1 A. At this time, hydrogen was added 250 cc / min, oxygen was 1.5 L / min. When the current was applied, the initial voltage was about 4.4 V and after 2100 hours the voltage was 4.35 V. In addition, the continuous operation of the segment SOFC module consisting of the five cells for 2100 hours and the change in the voltage measured thereon is shown in FIG.

In addition, the thermal cycle of the five-segment SOFC module is measured and shown in FIG. 3. The operating temperature was one cycle of 400 ° C. to 750 ° C., and a total of 43 thermal cycles were measured. The electrode area of the segment SOFC module was 9.5 cm ² , hydrogen was 300 cc / min and oxygen was 1.5 L / min.

Referring to FIG. 4, the overall voltage drop rate is 1.1%, and the result satisfies the voltage drop rate within 2% per 1000 hours of the quantitative target of the task. In addition, it was found that the segment SOFC composed of several unit cells is stable even in continuous operation. The rise in voltage at 1200 is due to the application of a current less than 0.1 A due to a malfunction of the electronic load.

Referring to FIG. 5, the initial OCV was measured at 5.03 V and after 43 heat cycles, the OCV was measured at 4.91 V. The OCV difference of the segment module means that there is no defect of the unit cell itself constituting the segment SOFC module at 0.08 V, and there is no gas leakage at the connection portion of the connecting material and the sus- tance tube.

Test Example  3: consisting of 10 cells Segment SOFC  Module performance evaluation

A 10-cell segment SOFC module was fabricated in the same manner as in Test Example 1 except that the anode was composed of 10 cells, and the anode was coated twice to form a 20 μm thick anode. Indicated. The I-V-P performance of the manufactured 10 cell segment SOFC module is measured and shown in FIG. 5.

Referring to FIG. 5, the 10-cell segment SOFC module exhibited excellent performance at OCV of 10.37 and 10.27 V at 700 ° C. and 750 ° C., respectively, and maximum power density of 233 and 332 mW / cm ² , respectively.

Test Example  4: Of electrolyte layer SEM  Photo analysis

SEM images of the surface and the cross-section of the electrolyte layer prepared using the slurry added with 10% by weight of 8 mol.% YSZ powder according to Example 1 of the present invention are shown in FIG. 6, and 8 mol according to Comparative Example 1 SEM images of the surface and the cross-section of the electrolyte layer prepared using the slurry added with 3% by weight of.% YSZ powder are shown in FIG. 7.

6 and 7, it can be seen that the electrolyte layer prepared in Example 1 according to the present invention is uniformly and densely formed, but cracks are formed on the surface of the electrolyte layer prepared in Comparative Example 1. .

The foregoing description is merely illustrative of the technical idea of the present invention, and various changes and modifications may be made by those skilled in the art without departing from the essential characteristics of the present invention. Therefore, the embodiments disclosed in the present invention are intended to illustrate rather than limit the scope of the present invention, and the scope of the technical idea of the present invention is not limited by these embodiments. The scope of protection of the present invention should be interpreted by the following claims, and all technical ideas within the scope equivalent thereto should be construed as being included in the scope of the present invention.

Claims (11)

A segmented solid oxide fuel cell submodule comprising a porous tubular support, a fuel electrode, an electrolyte layer, an air electrode, and a connecting member formed on an outer surface of the porous tubular support,
The porous tubular support is prepared by extrusion, drying, heat treatment and sintering of a paste prepared by kneading a mixture of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon powder, plasticizer, lubricant, binder and distilled water. The electrolyte layer is a segment-type solid oxide fuel cell submodule, characterized in that manufactured using a slurry containing 9.5 ~ 10.5% by weight of 8 mol% yttria stabilized zirconia powder relative to the total weight.
The method according to claim 1,
The porous tubular support is mixed, homogenized and powdered with 5 to 15 parts by weight of activated carbon based on 100 parts by weight of 3 mol% yttria stabilized zirconia;
With respect to 100 parts by weight of the mixed powder of 3 mol% yttria stabilized zirconia and activated carbon, 7 to 8 parts by weight of plasticizer, 6 to 7 parts by weight of lubricant, 17 to 18 parts by weight of binder, and 20 to 30 parts by weight of distilled water are mixed. Preparing a paste; And
Segmented solid oxide fuel cell submodule, characterized in that manufactured by performing the step of extruding, drying, heat treatment and sintering the paste.
The method according to claim 2,
Segmented solid oxide fuel cell submodule, characterized in that for mixing, homogenizing and powdering 10 parts by weight of activated carbon with respect to 100 parts by weight of the 3 mol% yttria stabilized zirconia.
The method according to claim 2,
Segmented solid oxide fuel cell submodule, wherein the activated carbon and distilled water are used in a weight ratio of 1: 1 when preparing the paste.
The method according to claim 2,
The step of heat-treating and pre-sintering the porous tubular support prepared by extruding the paste is heated to 0.67 ℃ / min per hour to 200 ℃ slowly burning the remaining water and additives, and maintained at 200 ~ 300 ℃ for 3 to 5 hours The binder is slowly burned, heated to 1 ° C./min up to 600 ° C., then maintained for 5 hours to completely burn the activated carbon, heated to 1.67 ° C./min to 1350-1500 ° C., and calcined for 3 to 5 hours. Segmented solid oxide fuel cell submodule, characterized in that.
The method according to claim 1,
The electrolyte layer formed on the outer surface of the porous tubular support is 8 mol% yttria stabilized zirconia powder 9.566-10.5 wt%, binder 0.9-1.1 wt%, homogenizer 0.19-0.21 wt%, dispersant 0.022-0.024 wt%, plasticizer 0.9-1.1 wt% Segmented solid oxide fuel cell submodule, characterized in that the coating on the anode using a slurry prepared by mixing a% and 87.066 to 88% by weight of the solvent.
A segmented solid oxide fuel cell module comprising a plurality of segmented solid oxide fuel cell submodules according to any one of claims 1 to 6.
The method of claim 7,
A segmented solid oxide fuel cell module comprising five or ten segmented solid oxide fuel cell submodules.
Preparing a porous tubular support using a paste comprising a mixture of homogenized and powdered 3 mol% yttria stabilized zirconia and activated carbon powder, a plasticizer, a lubricant, a binder and distilled water (S1);
Forming a fuel electrode on the porous tubular support (S2);
8 mol% yttria stabilized zirconia powder, a binder, a homogeneous agent, a dispersant, a plasticizer and a solvent are prepared on the anode to form an electrolyte layer using a paste (S3);
Forming an air electrode on the electrolyte layer (S4); And
Forming a connecting material for electrical connection (S5);
Segmented solid oxide fuel cell submodule manufacturing method comprising a.
The method of claim 9,
Preparing the porous tubular support (S1),
Mixing 5 to 15 parts by weight of the activated carbon powder with respect to 100 parts by weight of the 3 mol% yttria stabilized zirconia to prepare a slurry and homogenizing by ball milling;
Pulverizing and drying the mixture of the homogenized 3 mol% yttria stabilized zirconia powder and activated carbon powder to powder;
7 to 8 parts by weight of plasticizer, 6 to 7 parts by weight of lubricant, 17 to 18 parts by weight of binder, and 20 to 30 parts by weight of distilled water to prepare a paste, followed by extrusion into a tubular support, based on 100 parts by weight of the powdered mixture. ;
Inserting a metal bar into the tube of the extruded tubular support and drying at room temperature while rolling; And
Heat-treating the dried tubular support to completely burn the binder and activated carbon component added to the tubular support; And
Sintering the heat-treated tubular support, characterized in that it comprises a segment type solid oxide fuel cell submodule manufacturing method.
The method of claim 9,
In the forming of the electrolyte layer on the anode, the electrolyte layer may comprise 8 mol% yttria stabilized zirconia powder 9.566-10.5 wt%, binder 0.9-1.1 wt%, homogenizer 0.19-0.21 wt%, dispersant 0.022-0.024 wt%, plasticizer Method for producing a segmented solid oxide fuel cell submodule, characterized in that the slurry prepared by mixing 0.9 to 1.1% by weight of the solvent and 87.066 to 88% by weight of the solvent is coated on the anode using a vacuum slurry coating method and heat-treated. .

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