KR101381643B1 - Electrolyte materials for solid oxide fuel cell and preparing method of electrolyte for solid oxide fuel cell using the same - Google Patents

Abstract

The present invention relates to an electrolyte material for a multi-component solid oxide fuel cell having a perovskite structure and a method for producing an electrolyte for a solid oxide fuel cell using the same, and includes lanthanum (La), strontium (Sr), gallium (Ga), and magnesium. An electrolyte material of a solid oxide fuel cell comprising a five-component ceramic sintered body containing (Mg) and zinc (Zn) components, and a method of manufacturing an electrolyte for a solid oxide fuel cell using the same are provided.

Description

ELECTROLYTE MATERIALS FOR SOLID OXIDE FUEL CELL AND PREPARING METHOD OF ELECTROLYTE FOR SOLID OXIDE FUEL CELL USING THE SAME}

The present invention relates to an electrolyte material for a solid oxide fuel cell and a method for producing an electrolyte for a solid oxide fuel cell using the same, and more particularly, to an electrolyte material for a multi-component solid oxide fuel cell having a perovskite structure and a solid oxide fuel cell using the same. It relates to a method for producing an electrolyte.

A fuel cell is a power generation system that can obtain electrical energy and thermal energy by using hydrogen, which is spotlighted as the future infinite clean energy, as a fuel. Among them, solid oxide fuel cells (SOFCs) using ceramic oxygen ion conductors as electrolytes use chemical energy of fuel gas and oxygen gas such as hydrogen, natural gas and biogas at a high temperature of about 550 to 1000 ° C. It is a future power generation system that directly converts electrical energy and thermal energy through electrochemical reactions. These SOFCs are attracting attention as environment-friendly next generation power supply devices because they have the highest power conversion efficiency among various fuel cell types and have little pollutant emissions except water. In addition, high-temperature waste heat can be used as driving energy of gas turbine power generation system.In developed countries such as the US, Japan, and Europe, the combined power generation system using SOFC and gas turbine is recognized as the most promising distributed power generation system in the future. I am supporting. SOFC has the advantage of being able to use various hydrocarbon-based fuels such as natural gas in addition to high-purity hydrogen without reformer as it generates its own fuel reforming in comparison with polymer electrolyte fuel cells. This has the advantage of being high. The SOFC unit cell is composed of an electrolyte, a porous cathode (anode), and a fuel anode (cathode).

Oxygen in the air is converted into oxygen ions through the cathode (anode) of the SOFC, and the oxygen ions thus converted are diffused through the electrolyte to combine with hydrogen in the fuel gas at the anode (cathode) to generate electricity. Water is discharged. As such, the electrolyte in which oxygen ions diffuse and move is advantageous as the oxygen ion conductivity is higher, and it is important to secure a high sintered density so that air gas or fuel gas does not permeate. In addition, it is advantageous that the electrolyte serving as the support of the unit cell has high mechanical properties.

Currently, Yttria Stabilized Zirconia (YSZ) is a material widely used as an electrolyte for SOFC. YSZ is a material with high oxygen ion conductivity and has properties suitable for being used stably as an electrolyte of SOFC. However, when YSZ is used, there is a problem of operating at a high temperature of 1000 ° C. or higher in order to increase ion conductivity.

In addition, the crystal structure of the perovskite oxide is basically represented by ABO ₃ structure, where A is a cationic element having a large ion radius and B is a relatively small cationic element. The conventional perovskite electrolyte has a La atom and Based on the LaGaO ₃ material composed of Ga atoms at the B lattice point, a part of La having a trivalent oxidation number is replaced by 10-20 mol% with Sr having a divalent oxidation number, and a part of Ga having a trivalent oxidation number is divalent. It is an electrolyte composition in which oxygen ion vacancy was formed by substituting 15-20 mol% with Mg which has oxidation water. Such perovskite-based electrolytes are referred to as LSGM (La _{1 - x} Sr _x Ga _{1 - y} Mg _y O _{3 -z} , X = 0.1-0.2, Y = 0.15-0.2) electrolytes. In addition, to further improve the oxygen ion conductivity of the LSGM electrolyte, an LSGMC electrolyte in which part of Mg is replaced with Co having a smaller ion radius than Mg is now commercialized. However, LSGM electrolytes and LSGMC electrolytes generally have a high sintering temperature of 1400 ° C. or higher and are highly reactive with NiO, the anode component of SOFC. Therefore, when the LSGM electrolyte and the LSGMC electrolyte are coated on the anode support, which is NiO as the main component, and simultaneously sintered at 1400 ° C. or higher, there is a problem of deteriorating the output of the unit cell by forming a LaNiO ₃ reaction product having very poor conductivity from 1350 ° C.

Both cathode and electrolyte materials used in SOFC cells have an exponential increase in electrochemical properties as the operating temperature increases. Therefore, as the driving temperature of SOFC is increased, high output can be obtained. However, the stack is configured to produce actual power by stacking single cells and several cells manufactured by high temperature sintering by forming different kinds of ceramic materials in a multilayer structure. Stacks operate at high temperatures, causing a variety of problems. Representative problems include high temperature reaction with electrolyte and electrode material, deterioration of electrode characteristics due to continuous shrinkage of porous electrode, difficulty of high temperature sealing treatment using glass material, and high temperature oxidation of heat-resistant metal separator applied in flat panel cells. Destruction of the unit cell itself due to the volatility of chromium (Cr) or decrease in stack output.

The fundamental way to solve this problem is to lower the operating temperature. However, lowering the operating temperature drastically reduces the electrochemical properties of the electrode and electrolyte materials, making it impossible to expect the desired output. Therefore, there is a need for an electrolyte material having the same electrochemical properties as at high temperature driving even at low driving temperatures.

An object of the present invention is to provide an electrolyte for a solid oxide fuel cell that can lower the operating temperature of the fuel cell by allowing the electrolyte for the solid oxide fuel cell to be manufactured through the electrolyte material for the solid oxide fuel cell for low temperature sintering. In addition, it is another object to provide an electrolyte for a solid oxide fuel cell capable of maintaining the sintering density, that is, the density, suitable as an electrochemical property of the electrolyte and an electrolyte for the solid oxide fuel cell, while lowering the operating temperature of the solid oxide fuel cell.

The technical objects to be achieved by the present invention are not limited to the above-mentioned technical problems.

The electrolyte for a solid oxide fuel cell of the present invention for achieving the above object is made of a five-component ceramic sintered body containing lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg) and zinc (Zn) components. Can be.

Specifically, the composition of the lanthanum, strontium, gallium, magnesium and zinc components may be configured as shown in the following formula.

≪

La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8 (0.1 ≦ x ≦ 0.2, 0.15 ≦ _y ≦ 0.19, 0.01 ≦ _z ≦ 0.05, 0.8 ≦ (1-yz) ≦ 0.84).

The method for producing an electrolyte for a solid oxide fuel cell of the present invention for achieving the above object, by mixing a powder having a lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg) and zinc (Zn) components The method may include preparing a raw material powder, uniformly mixing the raw material powder prepared above, pulverizing and preparing a powder particle size, and sintering the synthesized raw powder at a predetermined temperature.

Specifically, the raw material powder, La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8 (0.1≤x≤0.2, 0.15≤y≤0.19, 0.01≤z≤0.05, 0.8≤ (1-yz) ≦ 0.84).

In the sintering step, the raw powder may be sintered at a temperature of 1200 ℃ ~ 1350 ℃.

In preparing the raw material powder, the powder having magnesium and zinc components may be at least one selected from water-insoluble oxide, water-soluble nitrate, water-soluble chloride, and water-soluble acetate powder.

As described above, the present invention has the effect of lowering the high sintering temperature of the perovskite-based electrolyte material previously used. In addition, by improving the oxygen ion conductivity at the same temperature as the existing perovskite-based electrolyte material, by providing an electrolyte having a high density suitable for a solid oxide fuel cell, it is possible to secure a high power density at the same temperature. In addition, by providing an electrolyte for a solid oxide fuel cell operable at a low temperature, there is an effect that can solve the high temperature durability problem, which is the biggest disadvantage of the solid oxide fuel cell.

1 is a scanning electron micrograph of an electrolyte material for a solid oxide fuel cell manufactured according to an embodiment of the present invention.
2 is a graph showing a powder particle size distribution constituting electrolyte materials according to the amount of zinc added in the electrolyte material according to an embodiment of the present invention.
3 is a flowchart illustrating a method of manufacturing an electrolyte material for a solid oxide fuel cell according to an embodiment of the present invention in order.
4 is an X-ray diffraction analysis of Comparative Examples and Examples 1 to 5.
5 is a scanning electron micrograph of the fracture surface of the sintered compact of Comparative Example and Example 2. FIG.
6 is a scanning electron micrograph of the fracture surface of the sintered compact of Comparative Example and Example 2. FIG.
7 is a scanning electron microscope photograph of the surface of the specimen of Example 2. FIG.
8 and 9 are graphs showing the results of X-ray diffraction analysis to determine the crystal structures of Comparative Example and Example 2, respectively.
10 is a graph showing the results of measuring oxygen ion conductivity of Comparative Examples and Examples.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same components are denoted by the same reference symbols whenever possible. In the following description, well-known functions or constructions are not described in detail since they would obscure the invention in unnecessary detail.

1 is a scanning electron micrograph of an electrolyte material for a solid oxide fuel cell manufactured according to an embodiment of the present invention.

The electrolyte material for a solid oxide fuel cell of the present invention is preferably made of a five-component ceramic sintered body containing lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg) and zinc (Zn) components.

Specifically, the electrolyte material for a solid oxide fuel cell of the present invention has a composition of the lanthanum, strontium, gallium, magnesium and zinc components as shown in the following formula (1).

≪ Formula 1 >

La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8 (0.1≤x≤0.2, 0.15≤y≤0.19, 0.01≤z≤0.05, 0.8≤ (1-yz) ≤0.84)

In general, the crystal structure of the perovskite oxide is basically a material having the structure of ABO ₃ , where A is a cationic element having a large ion radius and B is a relatively small cationic element. The conventional perovskite electrolyte has a portion of La having a trivalent oxidation number based on a LaGaO ₃ material composed of La atoms at A lattice points and Ga atoms at B lattice points to 10-20 mole% as Sr having divalent oxidation numbers. It is an electrolyte composition in which oxygen ion vacancies were formed by substituting 15 parts by mole of Ga having trivalent oxidized water by Mg having divalent oxidized water. Such perovskite-based electrolytes are referred to as LSGMs (La _{1 - x} Sr _x Ga _{1 - y} Mg _y O _{3 -z} , X = 0.1-0.2, Y = 0.15-0.2). In addition, in order to further improve the oxygen ion conductivity of the LSGM electrolyte, an LSGMC electrolyte in which a part of Mg is replaced with Co, Fe, or the like having a smaller ion radius than Mg has been commercialized. Conventional LSGM and LSGMC electrolytes typically have a high sintering temperature of 1400 ° C. or higher and are highly reactive with NiO, the anode component, and thus, when composed of a cathode support unit cell, the electrolyte is coated on the anode support, where NiO is a main component, and then 1400 ° C. or higher. When co-sintering at, it formed a LaNiO ₃ reaction product of very poor conductivity from 1350 ℃ or above to deteriorate unit cell output.

In order to solve this problem, in the present invention, the ion radius is larger than that of Mg, which is a constituent element of LSGM, and a small amount of Zn, which is a divalent oxide, is substituted for Mg to prepare an electrolyte material for a solid oxide fuel cell. The introduction of zinc (Zn) showed a sintering density of 95% or more suitable as an electrolyte even under sintering conditions of 1400 ° C. or less, which are the sintering temperatures of the conventional LSGM and LSGMC electrolytes. Therefore, the electrolyte material of the present invention can be sintered at a temperature lower than the sintering temperature of the conventional LSGM electrolyte and the LSGMC electrolyte, thereby suppressing the reaction with NiO, the anode component, and thus, may help to improve the output of the unit cell.

A particle size distribution of an electrolyte material for a solid oxide fuel cell according to a preferred embodiment of the present invention is shown in FIG. 2. 'D10' shown in FIG. 2 shows the particle size distribution of particles located at 10% from the smallest particles when the particles of the entire electrolyte material are arranged in order from smallest to smallest. In addition, 'D50' is the distribution of particles located from 50% to the smallest particles when particles of the entire electrolyte material are arranged in order from smallest to smallest, and 'D90' is 90% from the smallest particles. Indicates the distribution of these.

2 shows the size distribution of the powder particles constituting the electrolyte materials according to the amount of zinc added in the electrolyte material according to the embodiment of the present invention. Referring to Figure 2 it can be seen that the composition ratio of the substituted solid solution zinc component does not significantly affect the particle size distribution, the particle size of the powder constituting the electrolyte material according to a preferred embodiment of the present invention is about 0.3 ~ 1.3㎛ It can be seen that.

3 is a flowchart illustrating a method of manufacturing an electrolyte material for a solid oxide fuel cell according to an embodiment of the present invention in order.

To prepare an electrolyte material for a solid oxide fuel cell of the present invention, first, a raw powder is prepared, wherein the raw powder includes lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg), and zinc (Zn). It contains (S10). Thus, each powder containing each component is mixed in a predetermined container. At this time, each powder containing lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg) and zinc (Zn) components is weighed by a calculated amount in consideration of the composition of the final target electrolyte material. Put together in a container and mix.

At this time, the composition of the raw material powder is La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8 (0.1≤x≤0.2, 0.15≤y≤0.19, 0.01≤z≤0.05, 0.8≤ (1-yz) ≤ 0.84).

The present invention is prepared by substituting Zn for a portion of Mg in La, Sr, Ga, and Mg constituting a conventional LSGM electrolyte.

At this time, when the preferred amount of Zn is out of the above-described composition ratio, that is, when the z value representing the composition ratio of Zn in the formula showing the composition is less than 0.01, the electrical conductivity and sintered density of the electrolyte material according to the substitutional solid solution of Zn is improved compared with the conventional LSGM. The value is negligible and does not mean much. In addition, when exceeding 0.05, it is preferable not to exceed the conductivity because the conductivity is lowered than the conventional LSGM due to a decrease in crystallinity.

In preparing the predetermined powder having each component, the powder having magnesium and zinc components may be at least one selected from water-insoluble oxide, water-soluble nitrate, water-soluble chloride and water-soluble acetate powders. For example, to select a powder having a magnesium component in order to prepare a raw powder, a powder having a molecular formula of MgO, Mg (NO ₃ ) ₂ xH ₂ O, MgCl ₂ , or (CH ₃ COO) ₂ Mg may be selectively used. This is possible. In addition, a powder having a zinc component may also be selectively used as a powder having any molecular formula of ZnO, Zn (NO ₃ ) ₂ xH ₂ O, ZnCl ₂ , Zn (CH ₃ CO ₂ ) ₂ . Of course, even if it has a molecular formula not mentioned above, as the water-soluble nitrate-based, water-soluble chloride-based, water-soluble acetate-based powder as well as the water-insoluble oxide-based powder, any powder containing magnesium or zinc as a main component can be used.

The raw powder prepared as described above is pulverized to have a proper and uniform particle size as well as to be mixed with each powder uniformly (S20). A ball mill can be performed for uniform mixing and pulverization of the raw material powder. For the ball mill, the raw material powder is put in a predetermined container, a solvent such as ethanol is put in the container, and then a plurality of ceramic balls (balls), which serve to mix and pulverize powder, are put in a ball mill while rotating the container. The time for performing the ball mill may be about 2 hours to 36 hours. Of course, it is desirable to analyze the size of the ground particles and adjust the ball mill time until a particle size of the desired size is obtained. At this time, the raw material powder is not only uniformly mixed with the powders containing the respective components through the ball mill process but also finely pulverized the particles. In this case, the ball mill may be performed more than once, and the raw powder slurry prepared by performing the first ball mill may be dried in a hot air dryer. In addition, the dried slurry is further synthesized by further performing a calcined crystallization heat treatment at 1100 ~ 1300 ℃. Wet ball milling is performed once again to increase the sintering activation in the electrolyte sintering step by miniaturizing the particle size of the raw powder which is synthesized after calcination heat treatment and crystallization occurs. The ball mill at this time can be performed in the same manner as the above-described method. The calcined synthetic raw material particles may be final milled to about 0.3 ~ 1.3㎛ as described above.

Thereafter, the raw material powder synthesized above is molded and sintered (S30). The prepared raw powder can be molded into a disk using a pressure molding method. At this time, the synthesis of the raw material powder can be carried out by selecting an appropriate method, the raw material powder thus formed is sintered at a temperature of 1350 ℃ or less. At this time, it is preferable that the low-temperature sintering at 1200 ~ 1350 ° C and the sintering at the temperature can maintain the density and mechanical properties of the raw material powder. Sintering can be suitably selected according to the sintering density desired to be obtained within the range of 5 hours-20 hours.

The sintered body obtained by sintering in this way can be used as an electrolyte for a solid oxide fuel cell, and in this case, it can be manufactured as a solid oxide fuel cell by coating the anode on one side of the electrolyte and heat treatment by coating the cathode on the opposite side. Molding in the form of a disk described above may be carried out for use in the evaluation of the characteristics of the sintered body.

<Examples>

Prepared by weighing the respective powders with electronic balance using La ₂ O ₃ (99.99%), SrCO ₃ (99.9%), Ga ₂ O ₃ (99.99%), MgO (99.9%), ZnO (99.9%) do. Each prepared powder was placed in a predetermined container, ethanol was added as a solvent, and then ball milled using a partially stabilized zirconia ball having a diameter of 24 mm for 24 hours to uniformly mix the respective powders and at the same time have a finer particle size. It was ground to break. In Examples and Comparative Examples, the total weight of the mixed powder was 240-250 g, and the ethanol used as the solvent was blended at 300-400 L. The slurry, which was uniformly mixed and pulverized by a ball mill, was completely dried at a temperature of 70 ° C. in a hot air dryer for drying, and then synthesized by calcining heat treatment at 1200 ° C. for 10 hours. Powders synthesized by calcining heat treatment were again milled again by ball milling in the same manner as in the homogeneous mixing and grinding.

By the above method, the electrolyte materials of Examples 1 to 5 were prepared as shown in Table 1 below. Examples 1 to 5 were different in their composition and their compositions are shown in Table 1, respectively.

Meanwhile, in the comparative example, pure LSGM powder was prepared using only La ₂ O ₃ (99.99%), SrCO ₃ (99.9%), Ga ₂ O ₃ (99.99%), and MgO (99.9%).

division  Composition Comparative Example _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .2 O 2 .8 Example 1 _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .19 Zn 0 .01 O 2 .8 Example 2 _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .18 Zn 0 .02 O 2 .8 Example 3 _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .17 Zn 0 .03 O 2 .8 Example 4 _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .16 Zn 0 .04 O 2 .8 Example 5 _{La 0 .8 Sr 0 .2 Ga 0} .8 Mg 0 .15 Zn 0 .05 O 2 .8

In order to evaluate the characteristics of the electrolyte materials of Comparative Examples and Examples 1 to 5 shown in Table 1, the raw material powders of Examples and Comparative Examples were formed in the form of a flat disk having a size of 40 mm × 40 mm by uniaxial pressure molding. Molded and sintered to prepare a final electrolyte sintered body. For the crystal structure analysis of each example, X-ray diffraction analysis was performed in the same manner as the synthesis powder, and the surface and fracture surfaces were observed to observe the sintering characteristics of the specimen. In addition, each specimen was processed into a bar shape with a width of 2.5 mm, a length of 2.5 mm, and a length of 25 mm, and oxygen ion conductivity analysis was performed using a DC 4-terminal method.

Figure 4 is a result analyzed by X-ray diffraction analysis to confirm the crystallinity of the raw material powder synthesized in Comparative Examples and Examples 1 to 5 shown in Table 1. As confirmed in FIG. 4, Comparative Examples and Examples showed the same crystal structure, and it can be seen that the same level of secondary phase peaks were observed.

5 is a photograph of the fracture surface of the sintered body of Comparative Example and Example 2 by a scanning electron microscope, the result of sintering for 10 hours at 1430 ℃, which is a typical sintering temperature of the conventional LSGM after making each specimen It is shown. This shows similar microstructures at general sintering temperatures regardless of the solid solution of Zn in the examples and comparative examples of the present invention.

In addition, Figure 6 is a photograph of the fracture surface of the sintered body of Comparative Example and Example 2 by scanning electron microscopy, by sintering at 1300 ℃ for 10 hours by the method of the present invention after making each specimen The results are shown. As shown in Figure 6, the comparative example, that is, the conventional LSGM electrolyte can be seen that a large amount of pores appearing in a white sphere on the photo when compared to Example 2 when sintered at low temperatures. In contrast, Example 2 of the present invention, when sintered at low temperature, it can be seen that the structure is dense and the number of pores is smaller than in the prior art.

FIG. 7 is a scanning electron microscope photograph of the surface of the specimen of Example 2, which is the same as in FIG. 6 without breaking. The results also show a structure in which the powders are densely sintered as shown in FIG. 6. At this time, the average grain size is about 2 ~ 3um distribution.

8 and 9 are graphs showing the results of X-ray diffraction analysis to determine the crystal structures of Comparative Example and Example 2, respectively. At this time, each specimen was subjected to X-ray diffraction analysis in powder form. In this case, it can be seen that the result of the comparative example is increased in the secondary material compared with Example 2. This shows that the substitution solid solution effect of Zn can produce less secondary phase even at low synthesis temperature, which can be expected to lower the sintering temperature. Conventionally, powder was synthesized by calcining at a temperature of 1200 ° C., but in the case of substituting Zn for a part of Mg of LSGM as in the present invention, the secondary phase was suppressed compared to conventional LSGM while lowering the calcining synthesis temperature to 1100 ° C. as described above. You can see that you can.

Conventionally, since the sintering temperature of the electrolyte is higher than 1400 ° C., the anode and the electrolyte cannot be sintered at the same time. However, when the electrolyte material according to the embodiment of the present invention capable of low temperature sintering of 1350 ° C. or less, the anode and the electrolyte are sintered simultaneously. In this way, the fuel cell can be manufactured as a fuel cell, thereby suppressing reactivity with NiO, simplifying the manufacturing process, and consequently, achieving an economic effect by reducing energy.

FIG. 10 is a graph showing the results of measuring oxygen ion conductivity after preparing raw powders of Comparative Examples and Examples shown in Table 1 and sintering at 1300 ° C. to prepare specimens. As shown in FIG. 10, the ion conductivity measurement results of Examples 1 to 3 in which Zn was substituted and dissolved in LSGM showed about 20% higher oxygen ion conductivity than the comparative example of pure LSGM. This is a result of the operating temperature range of the solid oxide fuel cell above 600 ℃, it is confirmed that the ionic conductivity of 0.03 ~ 0.04S / cm of the same level as the YSZ electrolyte which is the most widely used electrolyte for the solid oxide fuel cell It can be seen that the electrolyte material according to the embodiment of the present invention can be used as a low-temperature electrolyte that can be sufficiently used even at 650 ° C.

Thus, according to the present invention, there is an effect of lowering the high sintering temperature of the conventional perovskite-based electrolyte material, and not only improves oxygen ion conductivity at the same temperature as the existing perovskite-based electrolyte material, but also applies to the solid oxide fuel cell. By providing an electrolyte having a suitable density, it is possible to secure a high output density at the same temperature. In addition, by providing an electrolyte for a solid oxide fuel cell operable at a low temperature, there is an effect that can solve the high temperature durability problem, which is the biggest disadvantage of the solid oxide fuel cell. In addition, since high oxygen ion conductivity can be ensured even at low temperatures, it can be used as a low-temperature electrolyte for fuel cells.

The electrolyte material for a solid oxide fuel cell as described above and a method for manufacturing an electrolyte for a solid oxide fuel cell using the same are not limited to the configuration and operation of the embodiments described above. The above embodiments may be configured such that various modifications may be made by selectively combining all or part of the embodiments.

Claims (6)

Based on the chemical formula (ABO ₃ ) of the perovskite oxide, lanthanum (La) and strontium (Sr) at the A-lattice point, gallium (Ga), magnesium (Mg) and zinc (Zn) at the B-lattice point An electrolyte material for a solid oxide fuel cell comprising a component as shown in the following chemical formula, and having a sintered density of 95% or more at 1,300 ° C. or lower and an ion conductivity of 0.1 S / cm or higher at 800 ° C.
&Lt;
La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8
0.1≤x≤0.2
0.15≤y≤0.19
0.01≤z≤0.05
0.8≤ (1-yz) ≤0.84
delete Preparing a raw powder by mixing a powder having a lanthanum (La), strontium (Sr), gallium (Ga), magnesium (Mg) and zinc (Zn) components;
Uniformly mixing the prepared raw powder and pulverizing to have a set powder particle size and synthesizing; And
And sintering the synthesized raw material powder at a set temperature.
The raw material powder,
La _1-x Sr _x Ga _1-yz Mg _y Zn _z O _2.8 (0.1≤x≤0.2, 0.15≤y≤0.19, 0.01≤z≤0.05, 0.8≤ (1-yz) ≤0.84) Method for producing electrolyte for fuel cell.
delete The method of claim 3,
In the sintering step,
A method for producing an electrolyte for a solid oxide fuel cell, wherein the raw material powder is sintered at a temperature of 1200 ° C to 1350 ° C.
The method of claim 3,
In the step of preparing the raw powder,
The magnesium and the zinc-containing powder is at least one selected from water-insoluble oxide, water-soluble nitrate, water-soluble chloride, and water-soluble acetate-based powder.

Images