KR20190045622A - Sealant composition for solid oxide fuel cell, solid oxide fuel cell comprising sealant manufactured by the same and method for sealing thereof - Google Patents

Abstract

The present invention relates to a sealing material composition for a solid oxide fuel cell, a solid oxide fuel cell having a sealing material manufactured by the same, and a sealing method thereof. The sealing material composition comprises SiO_2, B_2O_3, Al_2O_3, and BaO, and further comprises at least one of CaO, ZnO, Li_2O, Na_2O, and K_2O. The sealing material manufactured from the sealing material composition according to the present invention has an advantage of high physical stability.

Description

TECHNICAL FIELD [0001] The present invention relates to a sealing material composition for a solid oxide fuel cell, a solid oxide fuel cell having the sealing material made therefrom, and a sealing method thereof, and a sealing method thereof. BACKGROUND OF THE INVENTION 1. Field of the Invention [0001]

TECHNICAL FIELD The present disclosure relates to a sealing material composition for a solid oxide fuel cell, a solid oxide fuel cell having the sealing material produced thereby, and a sealing method thereof.

Recently, as the exhaustion of existing energy resources such as oil and coal is predicted, interest in energy that can replace them is increasing. As one of such alternative energies, fuel cells have attracted particular attention due to their advantages such as high efficiency, no emission of pollutants such as NOx and SOx, and abundant fuel.

A fuel cell is a power generation system that converts the chemical reaction energy of a fuel and an oxidant into electric energy. Hydrogen, hydrocarbons such as methanol and butane are used as fuel, and oxygen is used as an oxidant.

BACKGROUND ART Fuel cells include a polymer electrolyte fuel cell (PEMFC), a direct methanol fuel cell (DMFC), a phosphoric acid fuel cell (PAFC), an alkaline fuel cell (AFC), a molten carbonate fuel cell (MCFC) And a battery (SOFC).

1 schematically illustrates an electricity generation principle of a solid oxide fuel cell. The solid oxide fuel cell includes an electrolyte layer and an anode and a cathode formed on both surfaces of the electrolyte layer. do. 1 showing the principle of electricity generation of a solid oxide fuel cell, air is electrochemically reduced in the air electrode to generate oxygen ions, and the generated oxygen ions are transferred to the fuel electrode through the electrolyte layer. In the fuel electrode, fuel such as hydrogen, methanol, butane and the like is injected and the fuel is combined with oxygen ions and electrochemically oxidized to generate electrons and generate water. This reaction causes electrons to migrate to the external circuit.

On the other hand, the solid oxide fuel cell comprises a unit cell composed of an air electrode, an electrolyte, and a fuel electrode, and a plurality of unit cells are stacked to form a stack. For this stacking, the air electrode of one unit cell and the fuel electrode of the other unit cell must be electrically connected, and a structure capable of supplying fuel and air to each unit cell is required, and a metal separator is used for this purpose. At this time, sealing between the metal separator plate and the unit cell elements for preventing mixing of hydrogen as a fuel gas and air as a combustion gas in the fuel cell stack, prevention of gas leakage to the outside of the stack, and insulation between unit cells It is important.

That is, the fuel gas and the air have to be moved only through a predetermined path. When the fuel gas and the air are mixed or leaked out, the performance of the battery is rapidly deteriorated, and a high level of sealing technology is required.

Korean Patent Publication No. 2003-0045324 (published on Jun. 11, 2003)

The present disclosure provides a sealing material composition for a solid oxide fuel cell, a solid oxide fuel cell having the sealing material made therefrom, and a sealing method thereof.

The present invention relates to a sealing material composition for a solid oxide fuel cell, wherein the sealing material composition for solid oxide fuel cells comprises SiO ₂ at 31 mol% to 40 mol% B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; From 0 mol% to 10 mol% of Na ₂ O; And K ₂ O in an amount of 0 mol% to 10 mol%, wherein the sealing material composition has a glass transition temperature of 610 ° C or more and less than 660 ° C.

The present disclosure also provides a solid oxide fuel cell comprising a sealing material sealed at 750 DEG C or less using the sealing material composition described above.

The present invention also provides a battery module comprising the above-described solid oxide fuel cell as a unit cell.

Further, the present specification is concerned with an SiO ₂ film containing 31 mol% or more and 40 mol% or less; B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; From 0 mol% to 10 mol% of Na ₂ O; And K ₂ O in an amount of 0 mol% or more and 10 mol% or less, wherein the glass transition temperature of the sealing material composition is 610 Lt; 0 > C to less than 660 [deg.] C.

The sealing material made of the sealing material composition according to the present disclosure has an advantage of high physical stability.

The sealing material made of the sealing material composition according to the present disclosure has an advantage of high chemical stability.

The sealing material made of the sealing material composition according to the present disclosure has an advantage of high thermal stability.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic diagram showing an electricity generation principle of a solid oxide fuel cell (SOFC). FIG.
2 is a perspective view of a solid oxide fuel cell having a sealing material according to an embodiment of the present invention.
FIG. 3 shows the result of measurement of the sealing material before the driving and the sealing material after the driving for 1000 hours in Experimental Example 2 with a scanning electron microscope (SEM).
FIG. 4 shows the result of analysis of the shrinkage rate according to the pressure of Experimental Example 3 and the adhesive property between the substrate and the substrate by a high-temperature microscope.

Hereinafter, the present invention will be described in detail.

The present specification is concerned with a composition comprising SiO _{2 of not} less than 31 mol% and not more than 40 mol% B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; From 0 mol% to 10 mol% of Na ₂ O; And from 0 mol% to 10 mol% of K ₂ O. The present invention also provides a sealing material composition for a solid oxide fuel cell,

The thermal expansion coefficient of the sealing material may be similar to the thermal expansion coefficient of the oxygen ion conductive inorganic material of the solid oxide fuel cell. Specifically, the thermal expansion coefficient of the sealing material may be 10 × 10 ^-6 or more and 10.5 × 10 ^-6 or less. In this case, mismatch of the thermal expansion property with the SOFC cell can be minimized, and the occurrence of thermal stress due to the thermal cycle can be suppressed.

The glass transition temperature of the sealing material composition may be 610 캜 or higher. Specifically, the glass transition temperature of the sealing material composition may be 610 ° C or more and less than 660 ° C, more specifically, 610 ° C or more and 650 ° C or less. In this case, since the glass transition temperature is higher than the driving temperature of the solid oxide fuel cell, the thermal durability is good.

The sealing material composition for a solid oxide fuel cell may comprise glass powder.

Here, the glass powder means a powder of a material in a glass state. In this case, the glass state means a state in which the molten liquid cools without being crystallized by cooling, and the inorganic substance in the glass state is referred to as glass. The glass powder may be a powder of oxide glass. Specifically, the glass powder may be a powder of glass containing silicon dioxide (SiO ₂ ).

The glass powder includes SiO ₂ , B ₂ O ₃ , Al ₂ O _3, and BaO, and may further include at least one of CaO, ZnO, Li ₂ O, Na ₂ O, and K ₂ O.

In the case where the sealing material composition is composed of only glass powder, the sealing material composition may include SiO _{2 in an} amount of 31 mol% or more and 40 mol% or less based on the sealing material composition; B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; From 0 mol% to 10 mol% of Na ₂ O; And 0 mol% or more than 10 mol% may include K ₂ O.

Based on the glass powder, the sealing material composition comprises 31 mol% or more and 40 mol% or less of SiO _{2 when} the sealing material composition further includes an additional composition in addition to the glass powder; B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; 0 mol% or more Na ₂ O less than or equal to 10 mole%; And 0 mol% or more than 10 mol% may include K ₂ O.

The content of the glass powder may be 40 wt% or more and 80 wt% or less based on the total weight of the sealing material composition.

The sealing material composition may further include at least one of a binder, a plasticizer, a dispersant, and a solvent. The binder, plasticizer, dispersant and solvent are not particularly limited, and conventional materials known in the art can be used.

The binder may be a copolymer (PBMA-PEHMA) of poly (butyl methacrylate) (PBMA) and poly (2-ethylhexyl methacrylate) And may include at least one of Ethyl cellulose (EC), Polyvinylisobutyral (PViB), and Poly (2-ethylhexylacrylate) (PEHA).

The content of the binder may be 1 wt% or more and 20 wt% or less based on the total weight of the sealing material composition.

The plasticizer may be a commercial product such as dibutyl phthalate (DBP), di-2-ethylhexyl phthalate (DOP), di-isononyl phthalate (DINP) Di-isodecyl phthalate (DIDP), and Butyl benzyl phthalate (BBP).

The content of the plasticizer may be 0.1 wt% or more and 5 wt% or less based on the total weight of the sealing material composition.

The dispersant may be at least one of BYK-110, BYK-111 and BYK-112.

The content of the dispersant may be 5 wt% or more and 15 wt% or less based on the total weight of the sealing composition.

The solvent is not limited so long as it is easy to disperse the glass powder and remove it from the film or the green sheet, and conventional materials known in the art can be used. For example, the solvent may comprise at least one selected from water, isopropanol, toluene, ethanol, n-propanol, n-butyl acetate, ethylene glycol, butyl carbitol (BC) and butyl carbitol acetate .

The content of the solvent may be 10 wt% or more and 40 wt% or less based on the total weight of the sealing material composition.

The shrinkage percentage of the sealing material composition may be 44% or more, specifically 44% or more and 80% or less, more specifically 45% or less after raising the temperature from room temperature to 750 ° C at a rate of 5 ° C / Or more and 70% or less.

The present disclosure provides a solid oxide fuel cell comprising a sealing material sealed at 750 DEG C or less using the sealing material composition described above.

The solid oxide fuel cell may include a sealing material sealed by applying a pressure of 0.5 bar to 3 bar at 750 ° C or less using the sealing material composition. If the pressure is not applied or the pressure is less than 0.5 bar, the sealing will not be done. If the pressure is more than 3 bar, the sealing will be done but the battery cell will be broken.

The solid oxide fuel cell may include an air electrode, a fuel electrode, and an electrolyte layer provided between the air electrode and the fuel electrode.

The electrolyte layer may contain an oxygen ion conductive inorganic substance and is not particularly limited as long as it has oxygen ion conductivity. Specifically, the oxygen ion conductive inorganic material of the electrolyte layer includes a composite metal oxide including at least one selected from the group consisting of a zirconium oxide-based material, a cerium oxide-based material, a lanthanum oxide-based material, a titanium oxide-based material, and a bismuth oxide- . More particularly, the oxygen ion conductive inorganic material of the electrolyte layer are yttria (yttria) stabilized zirconium oxide (zirconia) (YSZ: (Y 2 O 3) x (ZrO 2) 1-x, x = 0.05 ~ 0.15), scandia Stabilized zirconium oxide (ScSZ: (Sc ₂ O ₃ ) x (ZrO ₂ ) _{1 -x} , x = 0.05 to 0.15), samarium doped ceria (SDC: (Sm ₂ O ₃ ) x (CeO ₂ ) x, x = 0.02 to 0.4) and gadolinium doped ceria (GDC: (Gd ₂ O ₃ ) x (CeO ₂ ) 1-x, x = 0.02 to 0.4).

The air electrode may include an oxygen ion conductive inorganic material. The inorganic particles are not particularly limited as long as they have oxygen ion conductivity, but those commonly used in the art can be employed.

For example, the inorganic material of the air electrode is yttria (yttria) stabilized zirconium oxide (zirconia) (YSZ: (Y 2 O 3) x (ZrO 2) 1-x, x = 0.05 ~ 0.15), scandia stabilized zirconia ( _{ScSZ: (Sc 2 O 3)} x (ZrO 2) 1-x, x = 0.05 ~ 0.15), samarium-doped ceria (ceria) (SDC: (Sm 2 O 3) x (CeO 2) 1-x, x = 0.02 to 0.4), gadolinium doped ceria (GDC: (Gd ₂ O ₃ ) x (CeO ₂ ) 1-x, x = 0.02 to 0.4), 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 oxide Lithium cobalt oxide (Samarium strontium cobalt oxide: SSC), barium strontium cobalt ferrite (Barium Strontium cobalt ferrite: BSCF), and lanthanum strontium gallium magnesium oxide (Lanthanum strontium gallium magnesium oxide: LSGM) may include at least one of.

The anode may contain an oxygen ion conductive inorganic material. The inorganic material of the anode is not particularly limited as long as it has oxygen ion conductivity, but those generally used in the art can be employed.

For example, as the inorganic substance of the fuel electrode, a cermet in which nickel oxide is mixed with the same inorganic substance as the oxygen ion conductive inorganic substance contained in the above-described electrolyte may be used.

The sealing material may seal the side surface of the solid oxide fuel cell in which the air electrode, the electrolyte layer, and the fuel electrode are sequentially stacked, in order to prevent the mixing of the fuel gas and the air as the combustion gas and to prevent the gas from leaking to the outside.

The sealing material may seal the sides of the solid oxide fuel cell, which are provided outside the air electrode and outside the fuel electrode, respectively, and between the separators provided with the fuel gas or air flow path and the air electrode, the electrolyte layer and the fuel electrode sequentially laminated.

The solid oxide fuel cell may have a driving temperature of 600 ° C or more and 700 ° C or less, and more specifically, a driving temperature of 600 ° C or more and 650 ° C or less.

The present invention provides a battery module including the above-described solid oxide fuel cell as a unit cell.

Wherein the battery module comprises: a stack including a unit cell including the solid oxide fuel cell and a separator provided between the unit cells; A fuel supply unit for supplying fuel to the stack; And an oxidant supply for supplying the oxidant to the stack.

And a unit cell comprising an air electrode, an electrolyte layer, and a fuel electrode, wherein a plurality of unit cells are stacked to form a stack, wherein the sealing material prevents fuel gas from mixing with air as a combustion gas, Thereby sealing the gap between the separator and the unit cell component for insulation between the unit cells.

The battery module may be specifically used as a power source for an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a power storage device.

The present specification is concerned with a composition comprising SiO _{2 of not} less than 31 mol% and not more than 40 mol% B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%; From 15 mol% to 20 mol% of Al ₂ O ₃ ; BaO of 5 mol% or more and 15 mol% or less; CaO of 0 mol% or more and 5 mol% or less; 0 mol% to 10 mol% of ZnO; Li ₂ O of 0 mol% or more and 5 mol% or less; From 0 mol% to 10 mol% of Na ₂ O; And K ₂ O in an amount of 0 mol% or more and 10 mol% or less, and sealing the solid oxide fuel cell at 750 ° C or less using the sealing material composition for a solid oxide fuel cell, .

The above-described method for manufacturing the sealing material for a solid oxide fuel cell can be referred to above for the constitution of the sealing material composition for a solid oxide fuel cell.

The step of sealing the solid oxide fuel cell comprises: disposing the sealing material composition to produce a gasket; And drying the gasket to produce a sealing material.

The drying temperature of the gasket may be 80 deg. C or higher and 150 deg. C or lower.

The drying time of the gasket may be 30 minutes or longer and 24 hours or shorter.

The step of sealing the solid oxide fuel cell comprises tape casting the sealant composition; And drying the tape cast composition to produce a sealant.

The drying temperature of the tape-cast composition may be from 80 ° C to 150 ° C.

The drying time of the tape cast composition may be from 1 hour to 24 hours.

A method of manufacturing a sealing material for a solid oxide fuel cell according to the present invention includes the steps of preparing a unit cell of a solid oxide fuel cell including an air electrode, a fuel electrode, and an electrolyte layer provided between the air electrode and the fuel electrode; A method for manufacturing a fuel cell stack, comprising: preparing a stack including a unit cell including a solid oxide fuel cell and a separator provided between the unit cells; Attaching a tape-cast sealing material to the surface of the unit cell and the surface of the separator using the sealing material composition; And heat treating the sealing material.

The heat treatment of the sealing material may be performed by a separate heat treatment process before the battery is driven, or the sealing material may be heat treated by the battery operating temperature.

The heat treatment temperature of the sealing material may be 750 캜 or lower.

The step of heat-treating the sealing material may include compressing the sealing material at 750 ° C or less to seal the solid oxide fuel cell. As described above, when the sealing material is compressed and heat-treated, the sealing material can be sealed at a temperature lower than a temperature at which the sealing material can be sealed.

The heat treatment temperature of the sealing material may be 600 ° C or higher and 750 ° C or lower, specifically 650 ° C or higher and 750 ° C or lower.

The heat treatment time of the sealing material may be from 1 hour to 10 hours.

The pressure for compressing the sealing material during the heat treatment of the sealing material may be 0.5 bar or more and 3 bar or less, specifically 0.5 bar or more and 2 bar or less, more specifically 0.5 bar or more and 1 bar or less.

Hereinafter, the present invention will be described in more detail by way of examples. However, the following embodiments are intended to illustrate the present disclosure and are not intended to limit the present disclosure.

[Example]

[Example 1]

Glass powders were combined so that the ingredients of each component were as shown in the following Table 1 (mol%), and the glass powders were melted by heating at a temperature of 1500 캜 for 5 hours using a platinum crucible. During the melting, a platinum stirrer was inserted and the glass was homogenized by stirring for 1 hour. Subsequently, the molten glass was quenched at room temperature to obtain glass. On the other hand, for the obtained glass, the particle size after crushing was classified to a level of 1 탆 to 20 탆 and selected for use.

SiO ₂ B ₂ O ₃ Al ₂ O ₃ BaO CaO ZnO Li ₂ O Na ₂ O K ₂ O 35 36 16 6 One 2 One 2 One

(Sealing material) powder was added to 21 wt% of the binder solution (SOKEN LRRS001) dissolved in the toluene solvent (binder content in the binder solution was 10 wt%), and then the sealing material paste was applied using a paste mixer And a gasket pattern was formed through dispensing. The fabricated gasket was dried at 120 DEG C for 1 hour to prepare a sealing material.

[Comparative Example 1]

A sealing material was prepared in the same manner as in Example 1, except that glass powder having the thermo-physical properties of Comparative Example 1 was used instead of the glass powder having the composition of Table 1 as the glass powder.

[Comparative Example 2]

A sealing material was prepared in the same manner as in Example 1, except that glass powder having the thermo-physical properties of Comparative Example 2 was used instead of the glass powder having the composition shown in Table 1 as the glass powder.

[Comparative Example 3]

A sealing material was prepared in the same manner as in Example 1, except that glass powder having the thermo-physical properties of Comparative Example 3 was used instead of the glass powder having the composition of Table 1 as the glass powder.

[Experimental Example 1]

Glass transition temperature (Tg) and flowability of the glass powder of Example 1 and Comparative Examples 1 and 2 were obtained, and the temperature (Tf) to be bonded to the substrate was as shown in Table 2 below. At this time, the temperature (Tf) and the glass flow temperature (Tf) at which the flowability is established can be expressed by a sealing temperature or a half ball point. The glass powder is made into a pellet shape, When observing at elevated temperature with a high temperature microscope, the temperature at which the pellet forms a half ball due to flowability is shown.

T _g (° C) T _f (° C) Example 1 621 830 Comparative Example 1 588 760 Comparative Example 2 680 880 Comparative Example 3 663 865

[Experimental Example 2]

A unit cell having a GDC (gadolinium doped ceria) type anode, a GDC type electrolyte layer and a LSCF (Lanthanum strontium cobalt ferrite) type air electrode to which NiO is added is prepared and a separator is provided on both sides of the unit cell, The sealing member of Example 1 or Comparative Examples 1 and 2 was attached to the side surface of the unit cell and the surface of the separator.

The sealing materials of Example 1 and Comparative Examples 1 and 2 were heat-treated at a temperature of 750 ° C while being pressurized at a pressure of 1 bar, respectively, to seal the unit cells with a sealing material.

Then, the unit cell was driven at 600 DEG C for 1000 hours.

The sealed sealing material before driving and the sealing material after driving for 1000 hours were measured with a scanning electron microscope (SEM). The results are shown in Fig.

3, it can be seen that the battery of Comparative Example 2 is not sealed, and thus the unit cell can not be driven. In Comparative Example 1, it can be seen that the unit cell before the driving was sealed. However, after the cell was driven at a temperature of 600 ° C or higher, the sealing member of Comparative Example 1 had pores formed therein and the ability to seal the cell was lowered.

On the other hand, it can be seen that the sealing material of Example 1 having a flowability and a temperature (Tf) of 830 ° C to be adhered to the substrate is sealed at 750 ° C together with a pressure of 1 bar, and the unit cell is sealed .

[Experimental Example 3]

Example 1 and Comparative Examples 2 and 3 were measured with a high temperature microscope while raising the temperature from room temperature to 750 ° C at a rate of 5 ° C / min under a pressure of 1 bar and maintaining the temperature at 750 ° C for 1 hour, It was cooled to room temperature and the attached state was confirmed. The results are shown in FIG. 4 and Table 3. At this time, if the attachment state was good, the result was indicated by o, and if the attachment state was bad, the result was indicated by x.

Example 1 Comparative Example 1 Comparative Example 2 Comparative Example 3 Attachment ○ ○ × ×

4, it can be confirmed that the sealing material composition of Example 1 has a shrinkage ratio of 44% or more, and the adhesion state with the substrate is maintained after cooling to room temperature.

4, Comparative Examples 2 and 3 were shrunk to less than 44% at 750 ° C after the completion of the heating, and it was confirmed that the adhesion state with the substrate was not maintained after cooling to room temperature.

Claims (7)

As a sealing material composition for a solid oxide fuel cell,
The sealing material composition for a solid oxide fuel cell comprises
From 31 mol% to 40 mol% of SiO ₂ ;
B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%;
From 15 mol% to 20 mol% of Al ₂ O ₃ ;
BaO of 5 mol% or more and 15 mol% or less;
CaO of 0 mol% or more and 5 mol% or less;
0 mol% to 10 mol% of ZnO;
Li ₂ O of 0 mol% or more and 5 mol% or less;
From 0 mol% to 10 mol% of Na ₂ O; And
0 to 10 mol% K ₂ O,
Wherein the sealing material composition has a glass transition temperature of 610 캜 or more and less than 660 캜. The sealing material composition for a solid oxide fuel cell according to claim 1, wherein the sealing material composition has a shrinkage ratio of 44% or more after the temperature is raised from room temperature to 750 ° C at a rate of 5 ° C / min under a pressure of 1 bar. A solid oxide fuel cell comprising a sealing material sealed at 750 DEG C or less using the sealing material composition according to claim 1 or 2. The solid oxide fuel cell according to claim 3, wherein the solid oxide fuel cell has a driving temperature of 600 ° C or more and 700 ° C or less. A battery module comprising the solid oxide fuel cell according to claim 3 as a unit cell. From 31 mol% to 40 mol% of SiO ₂ ;
B ₂ O _{3 not} less than 36 mol% and not more than 40 mol%;
From 15 mol% to 20 mol% of Al ₂ O ₃ ;
BaO of 5 mol% or more and 15 mol% or less;
CaO of 0 mol% or more and 5 mol% or less;
0 mol% to 10 mol% of ZnO;
Li ₂ O of 0 mol% or more and 5 mol% or less;
From 0 mol% to 10 mol% of Na ₂ O; And
And sealing the solid oxide fuel cell at 750 占 폚 or below using a sealing material composition for a solid oxide fuel cell comprising K ₂ O in an amount of 0 mol% to 10 mol%
Wherein the sealing material composition has a glass transition temperature of 610 캜 or more and less than 660 캜. 7. The method of claim 6, comprising compressing the sealing composition at 750 DEG C or less to seal the solid oxide fuel cell.

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