KR101735650B1 - Metal air battery having dual perovskite structure - Google Patents

Abstract

The present invention provides a dual perovskite structure having high electrical conductivity, high activity, and high stability. A dual perovskite structure according to an embodiment of the present invention includes a first structure including a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure, the second structure comprising a second perovskite compound different from the first perovskite compound; .

Description

[0001] The present invention relates to a metal air battery having a dual perovskite structure,

The technical idea of the present invention relates to an electrode material. More particularly, the present invention relates to a dual perovskite structure composed of two perovskite crystal structure materials, a metal air cell comprising the same, a solid oxide fuel cell comprising the same, a solid oxide water- To a method of manufacturing a robust structure.

In recent years, solid oxide fuel cells and metal air cells have been actively studied as secondary replacements that can replace conventional lithium ion batteries.

A solid oxide fuel cell (SOFC) is a highly efficient, environmentally friendly electrochemical power generation technology that directly converts the chemical energy of a fuel gas into electrical energy. Since all components are solid, SOFC has a simple structure, relatively low cost, and is free from electrolyte loss and replacement and corrosion problems compared to other fuel cells. The metal air cell is a secondary battery technology which is much higher in energy density than the lithium ion battery having the highest energy density among currently used secondary batteries and is actively studied as a next generation energy source for electric vehicles and the like.

The solid oxide fuel cell and the metal air cell are required to have a noble metal catalyst such as platinum due to the slow oxygen reduction reaction, so that the manufacturing cost is high. In addition, Li ₂ CO ₃ compounds formed by side reactions of the cathode may deteriorate battery performance and shorten battery life. Therefore, it is required that the current collector composed of a carbon body or the like does not react with lithium ions or the like.

Further, the anode used as the catalyst has a problem that the anode electrode is rapidly destroyed by carbon deposition. Also, it is very important that the anode electrode should have a stable structure in a hydrogen environment, and at the same time maintain an electric conductivity higher than a certain value. There is a possibility that the performance of the anode may deteriorate during long-term use in such a hydrogen environment.

Therefore, development of an electrode material having high electrical conductivity at room temperature, high activity such as oxygen reduction reaction and oxygen generation reaction, and high stability is required.

Korean Patent No. 10-0975335

SUMMARY OF THE INVENTION The present invention provides an electrode material having high electrical conductivity, high activity, and high stability.

Another object of the present invention is to provide a metal air battery including the dual perovskite structure.

It is another object of the present invention to provide a solid oxide fuel cell including the dual perovskite structure.

It is another object of the present invention to provide a solid oxide water-receiving cell including the dual perovskite structure.

According to an aspect of the present invention, there is provided a dual perovskite structure comprising: a first structure including a first perovskite compound; And a second structure located outside the first structure to cover at least a part of the first structure and including a second perovskite compound different from the first perovskite compound.

In one embodiment of the present invention, the first perovskite compound may have a double layered perovskite crystal structure, and the second perovskite compound may have a single perovskite crystal structure.

In one embodiment of the present invention, the first perovskite compound may have a single perovskite crystal structure, and the second perovskite compound may have a double layer perovskite crystal structure.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound represented by the following formula (1).

≪ Formula 1 >

LnTO _3-隆

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, O is oxygen, is a positive number of 1 or less, and is a value that makes the compound of the formula (1) electrically neutral.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound represented by the following general formula (2).

(2)

Ln _x E _1-x T _y O _3-隆

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, , Y is a number of more than 0 and not more than 2.0, O is oxygen, and? Is a positive number of 1 or less, and the value of the compound of the formula (2) is an electrical neutrality.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound represented by the following general formula (3).

(3)

Ln _0.5 E _0.5 T _y O _{3 -?}

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, , O is oxygen, and the delta is a positive number of 1 or less, and the compound of formula (3) is a value that is electrically neutral.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound of the following formula (4).

≪ Formula 4 >

Ln _0.5 E _0.5 T _1.1 O _{3 -?}

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, O is oxygen, ? is a positive number of 1 or less, and the compound of the above formula (3) has a value of electrical neutrality.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include an NdCoO ₃ compound.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include an Nd _x Sr _1-x Co _y O _{3 -δ} compound. X is a number of more than 0 and less than 1.0, y is a number of not less than 0 and not more than 2.0, and? Is a positive number of not more than 1,

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include an Nd _0.5 Sr _0.5 Co _y O _{3 -δ} compound. Y is a number of more than 0 and less than 2.0, and? Is a positive number of 1 or less, and the value of the compound of the formula (3) is an electrical neutrality.

In one embodiment of the present invention, the first perovskite compound or the second perovskite compound may include an Nd _0.5 Sr _0.5 Co _1.1 O _{3 -δ} compound.

In one embodiment of the present invention, the first perovskite compound may include Nd _0.5 Sr _0.5 Co _1.1 O _{3 -δ} compound. The second perovskite compound may include an NdCoO ₃ compound.

In an embodiment of the present invention, the first structure may have a column shape extending in one direction, and the second structure may have a shape coated on the outside of the column shape.

In one embodiment of the present invention, the first structure may have a spherical shape, and the second structure may have a shape coated on the outer side of the spherical shape.

According to an aspect of the present invention, there is provided a method of manufacturing a dual perovskite structure, comprising: dissolving metal oxide precursors in a solvent to form a spinning solution; Spinning the spinning solution using an electrospinning method to form a mesh structure; And heat treating the mesh structure to form a dual perovskite structure.

In one embodiment of the present invention, the step of heat treating the mesh structure to form the dual perovskite structure comprises forming a first structure comprising the first perovskite compound from the metal oxide precursors ; And forming a second structure comprising a second perovskite compound different from the first perovskite compound from the metal oxide precursors and covering at least a portion of the first structure have.

In one embodiment of the present invention, the metal oxide precursors include Nd (NO ₃ ) ₃ 6H ₂ O and Co (NO ₃ ) ₂ 6H ₂ O, and the solvent is N, N'-dimethylformamide . ≪ / RTI >

According to an aspect of the present invention, there is provided a metal air cell comprising: a first structure including a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, A cathode comprising an electrode material composed of a robustate structure; An anode facing the cathode; And an electrolyte disposed between the cathode and the anode.

According to an aspect of the present invention, there is provided a solid oxide fuel cell comprising: a first structure including a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, A cathode comprising an electrode material composed of a robustate structure; An anode facing the cathode; And an electrolyte disposed between the cathode and the anode.

According to an aspect of the present invention, there is provided a solid oxide water receiving cell including a cathode for discharging hydrogen gas formed by decomposition of water; An anode disposed facing the cathode and discharging the oxygen gas formed by decomposition of the water; And an electrolyte disposed between the anode and the cathode to produce hydrogen and oxygen. The cathode comprising: a first structure comprising a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, And an electrode material composed of a lobstite structure.

According to an embodiment of the present invention, there is provided a dual perovskite structure including different perovskite materials.

Since the dual perovskite structure is capable of providing long-term stability by preventing unwanted side reactions while maintaining a perovskite structure and exhibiting excellent performance of oxygen reduction reaction and oxygen generation reaction, Can be increased, the stability can be increased, and the price can be reduced.

The dual perovskite structure can be used as an electrode material for a metal air cell, a solid oxide fuel cell, and a solid oxide electrolytic cell.

1 is a cross-sectional view illustrating a dual perovskite structure according to an embodiment of the present invention.
2 is a cross-sectional view illustrating a dual perovskite structure according to an embodiment of the present invention.
3 is a schematic view showing a single perovskite crystal structure for illustrating a dual perovskite structure according to an embodiment of the present invention.
4 is a schematic view illustrating a dual layer perovskite crystal structure for illustrating a dual perovskite structure according to an embodiment of the present invention.
5 is a flow chart illustrating a method of fabricating a dual perovskite structure, according to one embodiment of the present invention.
Fig. 6 is a schematic view showing an electrospinning device for performing an electrospinning method of a method of manufacturing an electrode material, in accordance with an embodiment of the present invention.
FIG. 7 is a schematic view showing a state in which a spinning solution is radiated in the electrospinning device of FIG. 3 according to an embodiment of the present invention. FIG.
8 is a schematic diagram illustrating a metal air cell including an electrode formed of an electrode material including a dual perovskite structure, according to an embodiment of the present invention.
9 is a schematic diagram illustrating a solid oxide fuel cell including an electrode formed of an electrode material including a dual perovskite structure, according to an embodiment of the present invention.
10 is a schematic diagram illustrating a solid oxide charge-transfer cell including an electrode formed of an electrode material including a dual perovskite structure, according to an embodiment of the present invention.
11 is a transmission electron microscope photograph showing a dual perovskite structure manufactured according to a temporal example of the present invention.
12 is a transmission electron microscope photograph showing a dual perovskite structure manufactured according to a temporal example of the present invention.
13 is a graph illustrating an oxygen reduction reaction of a dual perovskite structure manufactured according to an embodiment of the present invention.
14 is a graph showing the oxygen production reaction of a dual perovskite structure manufactured according to an embodiment of the present invention
FIG. 15 is a graph illustrating electron transport capability of a dual perovskite structure manufactured according to an embodiment of the present invention.

Hereinafter, the present invention will be described in more detail. In interpreting the terms or words used in the present specification and claims, it is to be understood that the interpretation of terms or words used herein is necessarily conventional, based on the principle that the inventor can properly define the concept of the term to describe its invention in the best way It is to be understood that the invention is not to be interpreted as being limited only by the precautionary sense, but should be construed in accordance with the meaning and concept consistent with the technical idea of the present invention as described in the present specification.

1 is a cross-sectional view showing a dual perovskite structure 1 according to an embodiment of the present invention.

Referring to FIG. 1, a dual perovskite structure 1 includes a first structure 2 and a second structure 3.

The first structure 2 may include a first perovskite compound and may be located inside the dual perovskite structure 1.

The second structure 3 may be located outside the first structure 2 so as to cover at least a part of the first structure 2. The second structure 3 may include a second perovskite compound different from the first perovskite compound.

The first structure 2 may have a column shape extending in one direction. For example, the first structure 2 may have a cylindrical shape or a prismatic shape such as a triangular prism, a square prism, or the like. However, the pillar shape of the first structure 2 is exemplary, and the technical idea of the present invention is not limited thereto. For example, the first structure 2 may have various shapes such as a flat plate shape. The first structure 2 may be formed using an electrospinning method or the like.

The second structure 3 may have a shape coated on the outside of the first structure 2. For example, the second structure 3 may have a shape coated on the outside of the columnar shape of the first structure 2. The second structure 3 may have a shape covering the entire outer side of the first structure 2 or may have a shape covering a part thereof. In addition, the thickness of the second structure 3 may be entirely uniform or non-uniform.

The actual structures of the first structure 2 and the second structure 3 are shown in Figs. 11 and 12 below.

2 is a cross-sectional view showing a dual perovskite structure 4 according to an embodiment of the present invention.

The dual perovskite structure 4 shown in FIG. 2 has a difference in shape as compared with the dual perovskite structure 1 shown in FIG. 1, and only the difference will be described below do.

Referring to FIG. 2, the dual perovskite structure 4 includes a first structure 5 and a second structure 6.

The first structure 5 may have a spherical shape. The second structure 6 may have a shape coated on the outside of the spherical shape of the first structure 5. However, the spherical shape of the first structure 5 is exemplary, and the technical idea of the present invention is not limited thereto. For example, the first structure 5 may have various shapes, such as an elliptical shape. The first structure 5 may be formed by a spraying method or the like.

Hereinafter, the materials constituting the first structure 2 and the second structure 3 of the dual perovskite structure 1 of FIG. 1 will be described. The following description is also applicable to the first structure 5 and the second structure 6 of the dual perovskite structure 4 of FIG. 2 in the same manner.

The first structure 2 and the second structure 3 may have different perovskite crystal structure materials. That is, the first perovskite compound constituting the first structure 2 and the second perovskite compound constituting the second structure 3 may be different materials. For example, the first perovskite compound may have a double layer perovskite crystal structure, and the second perovskite compound may have a single perovskite crystal structure. Alternatively, the first perovskite compound may have a single perovskite crystal structure, and the second perovskite compound may have a double layer perovskite crystal structure. Or the first perovskite compound and the second perovskite compound both have a single perovskite crystal structure, but the constituent materials may be different from each other. Or both the first perovskite compound and the second perovskite compound have a double layer perovskite crystal structure, but the constituent materials may be different from each other.

Hereinafter, the perovskite crystal structure material will be described.

3 is a schematic view showing a single perovskite crystal structure for explaining a dual perovskite structure 1 according to an embodiment of the present invention. 4 is a schematic view showing a dual layer perovskite crystal structure for illustrating a dual perovskite structure 1 according to an embodiment of the present invention.

Referring to FIG. 3, a single perovskite crystal structure can be expressed as ABO ₃ . Elements with large ionic radii such as rare earth elements, alkaline rare earths, and alkalines are located in the A-site at the corner of the cubic lattice, and the coordination number (CN) . A transition metal with a small atomic radius, such as Co and Fe, is located in the B-site, which is the body center of the cubic lattice, and an octahedron (6-coordinate system) is formed by oxygen ions. Finally, oxygen ions are located at each face of the cubic lattice.

These single perovskite crystal structures are generally structurally displaced when other materials are substituted on the A-site, and are mainly composed of elements located at the B-site, in the octahedron of BO ₆ consisting of six) there occurs a structural mutation.

Referring to FIG. 4, a double-layered perovskite structure is a crystal lattice structure in which two or more elements are regularly arranged on an A-site, and has a formula of AA'B ₂ O _{5 +} . Specifically, the bilayer perovskite crystal structure may have a crystal structure in which the lamination permutation of [AO] - [BO ₂ ] - [A'O] - [BO ₂ ] is repeated along the c axis. Here, A 'means that an element located at A is replaced with another element, and an element occupying A' may include elements having a large ion radius such as rare earth element, alkaline rare earth element, or alkaline, .

When the reduction is performed in a hydrogen atmosphere, the single perovskite crystal structure material can be changed into a double layer perovskite crystal structure material. Such a double layer perovskite crystal structure material may have an oxygen vacancy cluster to facilitate the movement of oxygen ions, thereby imparting improved ionic conductivity and improving thermal and chemical stability.

The double layer perovskite crystal structure may be separated into an aligned double perovskite crystal structure and an unoriented perovskite crystal structure depending on the element occupying the A and the element occupying the A '. When the difference between the size of the element occupying the A and the size of the element occupying the A 'is large, the layer A and the layer A' can be clearly separated from each other. Quot; On the other hand, when the difference in size is not large, A and A 'are not clearly distinguished from each other, and the regularity is degraded and arranged, which is referred to as an unaligned perovskite crystal structure. However, such an unoriented perovskite crystal structure can also be formed as an aligned double perovskite crystal structure according to a synthesis method, and an aligned double perovskite crystal structure can be formed as an unoriented perovskite crystal structure Structure.

The dual perovskite structure according to one embodiment of the present invention has the single perovskite type crystal structure or the double layer perovskite type crystal structure described above.

According to an embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound represented by the following formula (1).

≪ Formula 1 >

LnTO _3-隆

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, O is oxygen, is a positive number of 1 or less, and is a value that makes the compound of the formula (1) electrically neutral.

The Ln may include one or more elements selected from lanthanides and may include any one of neodymium (Nd), praseodymium (Pr), samarium (Sm), gadolinium (Gd) can do. The E may be an alkaline earth metal and may include, for example, any one of calcium (Ca), barium (Ba), strontium (Sr), or mixtures thereof. The T may be a transition metal and may include any one of, for example, cobalt (Co), iron (Fe), copper (Cu), manganese (Mn), nickel .

According to an embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound represented by the following general formula (2). The compound of formula (2) represents a case where a part of the lanthanide element (represented by Ln) is substituted with an alkaline earth metal element (represented by E) in the compound of formula (1).

(2)

Ln _x E _1-x T _y O _3-隆

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, , Y is a number of more than 0 and not more than 2.0, O is oxygen, and? Is a positive number of 1 or less, and the value of the compound of the formula (2) is an electrical neutrality.

According to an embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound of the following formula (3). The compound of formula (3) represents a compound having the same atomic fraction of the lanthanide element and the alkaline earth metal element in the compound of formula (2).

(3)

Ln _0.5 E _0.5 T _y O _{3 -?}

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, , O is oxygen, and the delta is a positive number of 1 or less, and the compound of formula (3) is a value that is electrically neutral.

According to an embodiment of the present invention, the first perovskite compound or the second perovskite compound may include a compound of the following formula (4). Wherein the atomic fraction of the lanthanide group element and the alkaline earth metal group element in the compound of Chemical Formula 4 is the same, and the transition metal element (represented by T) Represents a compound 1.1 times greater than the sum of the elements.

≪ Formula 4 >

Ln _0.5 E _0.5 T _1.1 O _{3 -?}

Wherein Ln is one or more elements selected from lanthanides, E is one or more elements selected from the group of alkaline earth metals, T is one or more elements selected from transition metals, O is oxygen, ? is a positive number of 1 or less, and the compound of the above formula (3) has a value of electrical neutrality.

The first perovskite compound or the second perovskite compound according to an embodiment of the present invention is a compound of the above formulas 1 to 4 wherein Ln is neodymium (Nd) and E is strontium Sr), and T may be cobalt (Co). Accordingly, the first perovskite compound or the second perovskite compound may include an NdCoO ₃ compound, or may include an Nd _x Sr _1-x Co _y O ₃ -δ compound (wherein x Is a number less than 1.0 and less than 1.0, and y is a number greater than 0 and less than 2.0), Nd _0.5 Sr _0.5 Co _y O _3-δ compound (wherein y is a number of more than 0 and less than 2.0), Nd _0.5 Sr _0.5 can include Co _1.1 O _3-δ compound.

For example, the first perovskite compound may include an Nd _0.5 Sr _0.5 Co _1.1 O ₃ -δ compound, and the second perovskite compound may include an NdCoO ₃ compound. Alternatively, the first perovskite compound may include an NdCoO ₃ compound, and the second perovskite compound may include an Nd _0.5 Sr _0.5 Co _1.1 O ₃ -δ compound.

However, the above-mentioned materials are illustrative, and the technical idea of the present invention is not limited thereto, and the first perovskite compound or the second perovskite compound may be a perovskite compound having various crystal structures Is also included in the technical idea of the present invention.

5 is a flowchart illustrating a method of manufacturing a dual perovskite structure (S100) according to an embodiment of the present invention.

Referring to FIG. 5, a method (S100) for manufacturing a dual perovskite structure comprises: (S110) forming a spinning solution by dissolving metal oxide precursors in a solvent; (S120) spinning the spinning solution using an electrospinning method to form a mesh structure; And heat treating the mesh structure to form a dual perovskite structure (S130).

The step of forming the spinning solution (S110) may be performed by dissolving the metal oxide precursors containing the constituent material of the final dual perovskite structure in a solvent.

The solvent may comprise a variety of solvent materials. For example, the solvent may be water, methanol, ethanol, acetone, benzene, toluene, hexane, acetonitrile, N, N'- dimethylformamide (DMF), dimethylsulfoxide (DMSO) NMP), methylene chloride (CH ₂ Cl ₂ ), chloroform (CH ₃ Cl), tetrahydrofuran (THF), polyvinylpyrrolidone (PVP) and mixtures thereof. However, such a solvent is illustrative, and the technical idea of the present invention is not limited thereto.

The step of forming the spinning solution (S110) may be carried out at an appropriate temperature for a suitable mixing time, for example at ambient temperature, or at a temperature in the range, for example, from 0 ° C to 100 ° C, RTI ID = 0.0 > 24 hours. ≪ / RTI >

The step of forming the mesh structure (S120) may be performed using an electrospinning method. The electrospinning method may spin the spinning solution onto a target substrate such as a collector substrate or a separate substrate disposed on the collector substrate to form a mesh structure. The target substrate may be removed after performing the step of performing the heat treatment (S130) after the formation of the mesh structure, or before the performing of the heat treatment (S130). The target substrate may have various shapes and materials and may have a shape such as, for example, a plate shape, a drum shape, parallel rods, a plurality of intersecting rods, or a grid shape, Or may comprise an insulating material such as a glass or polymer material.

Such an electrospinning method can be performed by an electrospinning apparatus, and such electrospinning apparatus and method will be described in detail with reference to FIG.

The step (S130) of heat treating the mesh structure to form the dual perovskite structure may be performed in a temperature range in which the dual perovskite structure can be formed from the mesh structure. The heat treatment step (S130) may be performed at a temperature in the range of, for example, 700 ° C to 1000 ° C, for example, at a temperature in the range of 800 ° C to 850 ° C. The heat treatment step (S130) may be performed under various atmospheres and may include, for example, an oxidizing atmosphere including an air atmosphere, an oxygen gas, a reducing atmosphere containing hydrogen gas or the like, or an argon gas or a nitrogen gas Lt; / RTI > The heat treatment step (S130) may be performed for a time ranging from 1 minute to 24 hours, for example. For example, the heat-treating step (S130) may be performed at a temperature of from about 800 [deg.] C to about 900 [deg.] C for about 1 minute to about 24 hours. For example, the heat treatment step (S130) may be performed in an air atmosphere at a temperature of about 850 DEG C for about 3 hours.

The step (S130) of heat treating the mesh structure to form the dual perovskite structure comprises: forming a first structure comprising the first perovskite compound from the metal oxide precursors; And forming a second structure comprising a second perovskite compound different from the first perovskite compound from the metal oxide precursors and covering at least a portion of the first structure have.

The dual perovskite structure formed by the manufacturing method (S100) of the dual perovskite structure of FIG. 5 may be a cathode or an anode electrode material such as a metal air cell, a solid oxide fuel cell, and a solid oxide water- Lt; / RTI >

6 is a schematic diagram showing an electrospinning apparatus 1000 that performs an electrospinning method of a method of manufacturing an electrode material, according to an embodiment of the present invention.

6, an electrospinning apparatus 1000 includes a spinning solution tank 10, a spinning nozzle 20, a spinneret nozzle tip 30, an external power source 40, and a collector substrate 50.

The spinning solution tank 10 may store the spinning solution 60. The spinning solution 60 may vary depending on the material to be spinned. The spinning solution 60 may contain a solution in which the metal oxide precursors are dissolved in a solvent, such as the spinning solution formed in the above-described production method (S100). The spinning solution tank 10 may pressurize the spinning solution 60 using a built-in pump (not shown) to provide the spinning solution 60 to the spinning nozzle 20.

The spinning nozzle 20 may receive the spinning solution 60 from the spinning solution tank 10 and spin the spinning solution 60 through the spinning nozzle tip 30 located at one end.

The spinneret nozzle tip 30 can spin the spinning solution 60 by the voltage applied by the external power source 40 after the spinning solution 60 is pressurized by the pump to fill the nozzle tube therein.

The external power supply 40 may provide a voltage such that the spinning solution 60 is radiated to the spinning nozzle 20. The voltage may vary depending on the type of spinning solution 60, the amount of spinning, the type of collector substrate 50, the process environment, and the like, and may range, for example, from about 100 V to about 30000 V, Lt; / RTI > As described above, the voltage applied by the external power supply 40 can radiate the spinning solution 60 filled in the spinneret nozzle tip 30. [

The collector substrate 50 is located below the spinneret 20 and receives the spinning solution 60 to be emitted. The collector substrate 50 may be grounded and accordingly have a ground voltage, for example, a voltage of 0V. Alternatively, the collector substrate 50 may have a voltage opposite to that of the spinneret 20. The positional relationship between the collector substrate 50 and the spinneret 20 is exemplary and the technical idea of the present invention is not limited thereto. For example, the case where the collector substrate 50 is positioned above the spinneret 20 and the spinning solution 60 radiated from the spinneret 20 emits in the upward direction is also included in the technical idea of the present invention. For example, the case where the collector substrate 50 is positioned horizontally with respect to the spinneret 20 and the spinning solution 60 radiated from the spinneret 20 is radiated in the horizontal direction is also included in the technical idea of the present invention. The collector substrate 50 may be on a horizontal axis or the same spatial axis as the spinneret 20.

The radiation nozzle 20 and the spinneret nozzle tip 30 are charged to a positive voltage or a negative voltage by the external power source 40 so that the spinning solution 60 is also charged, A voltage difference with the substrate 50 is generated. The spinning solution 60 at the end of the spinneret nozzle tip 30 may have a conical shape such as a Taylor cone when a voltage is applied to the spinneret 20 and the spinneret tip 30 by the external power source 40 . At this time, an electric field of about 50000 V / m to about 150000 V / m may be formed between the spinneret tip 30 and the spinning solution 60. By the voltage difference, the spinning solution 60 can be radiated to the collector substrate 50 and accommodated. This radiation principle can be referred to as electro-hydro dynamic inkjet or electro-spinning.

By controlling the flow rate of the spinning solution 60 and the voltage difference between the spinneret tip 30 and the collector substrate 50 the diameter and length of the fibers received in the collector substrate 50 by spinning solution 60 Can be controlled. For example, the fiber may have a thickness in the range of about 50 nm to 1 占 퐉 and a length in the range of about several 占 퐉 to several hundred 占 퐉.

FIG. 7 is a schematic view showing a state in which a spinning solution is radiated in the electrospinning apparatus 1000 of FIG. 3, according to an embodiment of the present invention.

Referring to Figure 7, the spinneret nozzle tip 30 may spin the spinning solution 60 in a linear form, for example in the form of a wire or a rod. Such radiation can be referred to as a spinning mode. The spinning solution 60 may be radiated in different forms depending on its physical properties such as the viscosity of the solution, the weight ratio of the solute in the solution, the type of solute and solution, and the molecular weight of the solute and solvent. Also, it can be radiated in different forms depending on the magnitude of the applied voltage. For example, the spinneret nozzle tip 30 may spin the spinning solution 60 in the form of a spray. This radiation can be referred to as a spray mode.

As shown in Fig. 7, when the spinning solution 60 is radiated in a linear form, the above-described network structure can be formed. Such a network structure may be arranged to constitute a one-dimensional, two-dimensional or three-dimensional network structure. For example, the network structure may be composed of a one-dimensional network structure in which a plurality of linear structures are connected in parallel and connected in a linear shape. For example, the network structure may be a two-dimensional network structure in which a plurality of linear-shaped structures are overlapped and connected to each other at a predetermined angle and connected in a planar shape. For example, the network structure may be composed of a three-dimensional network structure in which a plurality of linear-shaped structures are overlapped and connected to each other so as to have a predetermined angle and connected in a three-dimensional shape. The network structure may include various shapes, for example, a mesh shape or a web shape.

The dual perovskite structure formed by the manufacturing method (S100) of the dual perovskite structure of FIG. 5 may be a cathode or an anode electrode material such as a metal air cell, a solid oxide fuel cell, and a solid oxide water- Lt; / RTI >

8 is a schematic diagram illustrating a metal air cell 100 including an electrode formed of an electrode material including a dual perovskite structure, according to an embodiment of the present invention.

8, the metal air cell 100 includes an anode 110 as a cathode, a cathode 120 as an anode disposed facing the anode 110, and a cathode 120 disposed between the anode 110 and the cathode 120 And an electrolyte (130). The cathode 120 may further include a current collector 140 and a catalyst body 150. The anode 110 and the cathode 120 are disposed facing each other.

The metal air cell 100 generates electric power by using a reaction between metal and oxygen. The greatest advantage of the metal air cell 100 is that it uses oxygen existing in the natural world as an active material and possesses a very high theoretical energy density as compared with other secondary batteries and also possesses an affinity characteristic. In addition, since the metal air cell 100 does not contain a chemical oxidizer therein, there is no risk of explosion or fire, and the weight can be greatly reduced. In addition, it is very economical, superior in stability, and operates at low temperatures as compared with a fuel cell using hydrogen or alcohol.

The anode 110 may include a material that becomes a cation when it loses electrons at the time of discharging, and may include, for example, a metal and may include, for example, lithium, zinc, magnesium, aluminum, and calcium. In particular, lithium has a theoretical energy density of 11,140 Wh / kg, which is almost similar to that of gasoline at 13,000 Wh / kg. For reference, aluminum has a theoretical energy density of 8130 Wh / kg, calcium 4180 Wh / kg and zinc 1350 Wh / kg. In addition, the anode 110 may be formed using an electrode material including a dual perovskite structure according to the technical idea of the present invention.

The cathode 120 is configured to use oxygen in the air, and can collect the oxygen. The metal air cell 100 can theoretically reduce the weight of the cathode 120 to zero or drastically because the cathode 120 can use oxygen in the air. Therefore, since the weight of the anode 110 can be increased by reducing the weight of the cathode 120, the weight ratio of the anode 110 to the total weight of the metal air cell 100 is increased, It can provide a high energy density per unit weight.

The cathode 120 may be formed using an electrode material including a dual perovskite structure according to the technical idea of the present invention. For example, at least one of the current collector 140 and the catalyst body 150 may be formed using an electrode material including a dual perovskite structure according to the technical idea of the present invention.

For example, the cathode 120 may include a first structure comprising a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, And an electrode material composed of a lobstite structure.

The electrolyte 130 is disposed between the anode 110 and the cathode 120 and may include an electrolytic material. The electrolyte 130 may include, for example, a sodium hydroxide (NaOH) solution or a calcium hydroxide (KOH) solution. Also, the electrolyte 130 may be composed of a solid-phase medium.

Hereinafter, power generation in the metal air battery 100 will be described. The anode 110 and the cathode 120 may be subjected to a discharge reaction and a charging reaction. The discharge reaction in the anode 110 and the cathode 120 is as follows. The charging reaction is such that the following reactions are directed to the opposite echo. In the following reaction formula, "M" may be a metal as a material constituting the anode 110.

<Anode Reaction>

M -> M ⁺ + e ^-

<Cathode reaction>

2 (M ⁺ + e ^- ) + O ₂ - > M ₂ O ₂

The positive ions 170 formed on the anode 110 through the discharge reaction are directed to the cathode 120 through the electrolyte 130. At this time, the electrons whose positive and negative ions are lost pass through the load 190 through separate conductors, thereby supplying power to the load 190 as a result.

Oxygen 180 from the outside is supplied to the cathode 120 and the cation 170 reacts with the oxygen 180 and the cathode 120 to form an oxide. At this time, electrons passing through the load 190 are supplied to the cathode 120 to form the oxide together.

On the other hand, at the time of charging, the oxide is decomposed, and the cation acquires electrons and returns from the cathode 120 to the anode 110 through the electrolyte 130.

Figure 9 is a schematic diagram illustrating a solid oxide fuel cell 200 including an electrode formed of an electrode material comprising a dual perovskite structure, according to one embodiment of the present invention.

9, the solid oxide fuel cell 200 includes an anode 210, a cathode 220 disposed opposite the anode 210, and an anode 210 disposed between the anode 210 and the cathode 220, And an electrolyte 230 which is a solid oxide. And optionally a buffer layer 240 disposed between the anode 210 and the electrolyte 230.

Solid oxide fuel cells of the fuel 200, as shown in electrochemical reaction is the following reaction scheme, a cathode 220, oxygen gas O ₂ has an anode reaction and the anode 210, changing the oxygen ions O ^2- of the (H ₂ or hydrocarbon ) And oxygen ions that have moved through the electrolyte.

<Reaction Scheme>

Anode reaction: 1/2 O ₂ + 2e ^- -> O ^2-

Cathode reaction: H ₂ + O ^2- -> H ₂ O + 2e ^-

In the cathode 220 of the solid oxide fuel cell 200, oxygen adsorbed on the surface of the electrode is dissociated and diffused to form a triple phase boundary where the electrolyte 230, the cathode 220 and the pores (not shown) The oxygen ions are converted into oxygen ions, and the generated oxygen ions are transferred to the anode 210, which is a fuel electrode, through the electrolyte 230.

In the anode 210 of the solid oxide fuel cell 200, the moved oxygen ions combine with the hydrogen contained in the fuel to generate water. At this time, hydrogen evolves electrons to hydrogen ions (H ⁺ ) and binds to the oxygen ions. The discharged electrons move to the cathode 220 through wiring (not shown) to change oxygen to oxygen ions. Through this electron transfer, the solid oxide fuel cell 200 can perform the battery function.

The solid oxide fuel cell 200 can be fabricated using a conventional method known in the art, so a detailed description thereof will be omitted here. In addition, the solid oxide fuel cell 200 can be applied to various structures such as a tubular stack, a flat tubular stack, a planar type stack, and the like.

The solid oxide fuel cell 200 may be in the form of a stack of unit cells. For example, a unit cell (MEA) composed of an anode 210, a cathode 220, and an electrolyte 230 is stacked in series, and a separator plate (not shown) a stack of unit cells can be obtained with a separator interposed therebetween.

At least one of the anode 210 and the cathode 220 may be formed using an electrode material including a dual perovskite structure according to the technical idea of the present invention.

For example, the cathode 220 may include a first structure comprising a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, And an electrode material composed of a lobstite structure.

The electrolyte 230 is not particularly limited as long as it can be generally used in the art. For example, the electrolyte 230 may be a stabilized zirconia based system such as yttria stabilized zirconia (YSZ) and scandia stabilized zirconia (ScSZ); Ceria systems doped with rare earth elements such as samaria-doped ceria (SDC), gadolinia-doped ceria (GDC) and the like; Other LSGM ((La, Sr) (Ga, Mg) O ₃ ) system; And the like. In addition, the electrolyte 230 may include strontium or magnesium-doped lanthanum gallate.

The buffer layer 240 may be positioned between the anode 210 and the electrolyte 230 to provide a smooth contact. The buffer layer 240 may function to mitigate, for example, crystal lattice distortion between the anode 210 and the electrolyte 230. The buffer layer 240 may comprise, for example, LDC (La _0.4 Ce _0.6 O _{2 -δ} ). The buffer layer 240 may be omitted as an optional component.

10 is a schematic diagram illustrating a solid oxide water-dissipating cell 300 including an electrode formed of an electrode material including a dual perovskite structure, according to an embodiment of the present invention.

10, the solid oxide acceptance cell 300 includes an anode 310, a cathode 320 disposed opposite the anode 310, and an anode 310 disposed between the anode 310 and the cathode 320, And an electrolyte 330 which is a conductive solid oxide. The cathode 320 may be referred to as a hydrogen electrode because it is in contact with hydrogen gas, and the anode 310 may be referred to as an oxygen electrode in contact with oxygen gas.

The electrochemical reaction of the solid oxide water electrolytic cell 300 is performed by an anode reaction in which water (H ₂ O) in the cathode 320 is converted into hydrogen gas (H ₂ ) and oxygen ions (O ^2- ) And an anode reaction in which the oxygen ions that have been moved through the electrolyte 330 are converted into oxygen gas (O ₂ ). This reaction is opposite to the reaction principle of a typical fuel cell.

<Reaction Scheme>

Cathode reaction: H ₂ O + 2e ^- -> O ^2- + H ₂

Anode reaction: O ^2- -> 1/2 O ₂ + 2e ^-

When power is applied to the solid oxide electrolytic cell 300 from the external power supply 340, electrons are supplied from the external power supply 340 to the solid oxide electrolytic cell 300. The electrons react with water supplied to the cathode 320 to generate hydrogen gas and oxygen ions. The hydrogen gas is discharged to the outside, and the oxygen ions are transferred to the anode 310 through the electrolyte 330. The oxygen ions transferred to the anode 310 lose electrons and are converted into oxygen gas and discharged to the outside. The electrons flow to the external power source 340. Through this electron transfer, the solid oxide electrolytic cell 300 can electrolyze water to form hydrogen gas at the cathode 320 and oxygen gas at the anode 310.

At least one of the anode 310 and the cathode 320 may be formed using an electrode material including a dual perovskite structure according to the technical idea of the present invention.

For example, the cathode 320 may include a first structure comprising a first perovskite compound; And a second structure located outside the first structure to cover at least a portion of the first structure and including a second perovskite compound different from the first perovskite compound, And an electrode material composed of a lobstite structure.

The electrolyte 330 is not particularly limited as long as it can be generally used in the art. The electrolyte 330 may include the same material as the electrolyte 230 of the solid oxide fuel cell 200 described above with reference to FIG. 9, or may have the same structure.

[Example]

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The above embodiments are not intended to limit the scope of the present invention.

In order to form a dual perovskite structure, Nd _0.5 Sr _0.5 Co _1.1 O _3-隆 compound was selected as the first perovskite compound and NdCoO ₃ compound was selected as the second perovskite compound .

As the metal _{precursor, Nd (NO 3) 3 6H} 2 O (Aldrich, 99.9%, metal basis), Sr (NO 3) 2 (Aldrich, 99 +%), and _{Co (NO 3) 2 6H 2} O (Aldrich , 98 +%) was dissolved in N, N-dimethylformamide (DMF) (99.5%, Aldrich Chemical Co.) at a concentration of 0.01 M. At this time, the proportions of the metal precursors were adjusted so that the ratio of A to B was about 1: 1.1 so that Nd _0.5 Sr _0.5 Co _1.1 O _3-δ compound was formed. The solution was then mixed with 15 wt% PVP (Polyvinylpyrrolidone, Mw = 1,300,000, Aldrich Chemical Co.) to form a spinning solution.

The spinning solution was electrospun by using the electrospinning apparatus described above to form a mesh structure.

Then, the mesh structure was heat-treated at about 850 ° C for about 4 hours to form a dual perovskite structure.

_{Nd 0.5 Sr 0.5 Co 1.1 O 3} -δ has a compound, dual page lobe having a NdCoO ₃ compound as the second perovskite compound Sky tree structure as a, the first perovskite compound prepared as described above Will be described with reference to Figs. 11 to 15 below.

11 is a transmission electron microscope photograph showing a dual perovskite structure manufactured according to a temporal example of the present invention. FIG. 11 illustrates a bright field transmission electron microscopy (BFTEM) and a high resolution transmission electron microscopy (HRTEM).

Referring to FIG. 11, a second structural body having a columnar first structural body and particles having a small crystal size is disposed on a surface thereof. The surface showed rough surface morphology by the particles.

12 is a transmission electron microscope photograph showing a dual perovskite structure manufactured according to a temporal example of the present invention. FIG. 12 shows a scanning transmission electron microscope (STEM HAADF) and a high-resolution transmission electron microscope (HRTEM).

Referring to FIG. 12, the particles positioned on the surface of the dual perovskite structure of FIG. 11 exhibited orthorhombic NdCoO ₃ structures of 5.33, 7.54, and 5.34.

For example, in the development of zinc metal air cells, the slow oxygen reduction reaction is becoming the biggest problem. That is, in the battery discharge reaction, the OH ^- ion consumption rate at the zinc cathode is much larger than the OH ^- ion production rate at the cathode, so that the OH ^- ion concentration in the electrolyte is rapidly lowered, have. Therefore, in the field of secondary batteries, it is required to develop a material having a rapid oxygen reduction reaction.

Hereinafter, the oxygen reduction reaction and the oxygen generation reaction of the dual perovskite structure of the present invention will be described. The graphs of FIGS. 13 to 15 below were measured by a Rotating Ring Disk Electrode (RRDE) measurement method in a 0.1 M KOH electrolyte. In addition, the embodiment of the present invention is a dual perovskite structure composed of Nd _0.5 Sr _0.5 Co _1.1 O _3-δ compound and NdCoO ₃ compound, and a comparative example is a structure composed of Nd _0.5 Sr _0.5 Co _1.1 O _3-δ compound The test was carried out. The electrode was made using carbon.

13 is a graph illustrating an oxygen reduction reaction of a dual perovskite structure manufactured according to an embodiment of the present invention.

Referring to FIG. 13, the embodiment and the comparative example of the present invention show almost similar tendency in the graph form. Further, the embodiment and the comparative example of the present invention show similar tendency in the disk current (i _d ) value. However, as compared with the comparative example, the graph of the embodiment is entirely located on the lower side. This means that the embodiment starts the oxygen reduction reaction at the lower overvoltage and can also generate more current at the same voltage. The embodiment showed a current (i _d ) value of about -5 as the absolute value of the voltage increased. The oxygen reduction reaction characteristics of this embodiment means that the embodiment provides a fast oxygen reduction reaction and can generate a large amount of current. Such oxygen reduction reaction characteristics are expected to affect the dual perovskite structure of the present invention including two different perovskite materials and morphological characteristics as shown in FIG. A good catalyst for an oxygen reduction reaction must have an oxygen reduction reaction that starts at a lower voltage and generates a lot of current under the same voltage. Therefore, the dual perovskite structure of the present invention can be an excellent catalyst for the oxygen reduction reaction.

FIG. 14 is a graph showing the oxygen generation reaction of a dual perovskite structure manufactured according to an embodiment of the present invention.

Referring to FIG. 14, the embodiment and the comparative example of the present invention show almost similar tendency in the graph form. However, the embodiment of the present invention showed that the onset potential was decreased and the amount of current generated at the same voltage increased about twice as compared with the comparative example. It can be seen that the embodiment of the present invention has a catalytic effect which is particularly excellent for the oxygen generating reaction. In conjunction with FIG. 13, the embodiment of the present invention is an excellent catalyst for an oxygen reduction reaction as well as an oxygen reduction reaction, and is very suitable as a cathode catalyst for reversibly effecting these two reactions. In the case of using most of the oxide catalysts, a weak catalytic effect on the oxygen reduction reaction causes a low charge / discharge efficiency, and there is a limit in that the advantage in terms of the energy density of the metal air cell is discolored. In addition, conventionally, there is a limit to use the electrode material together with a carbon support which can cause side reactions because the electric conductivity of the electrode material is low. However, since the dual perovskite structure of the present invention has a high electrical conductivity, it is possible to form an electrode using one kind of material, so that undesired side reactions can be minimized.

FIG. 15 is a graph illustrating electron transport capability of a dual perovskite structure manufactured according to an embodiment of the present invention.

Referring to FIG. 15, the embodiment and the comparative example of the present invention show almost similar tendency in the graph form. However, the embodiment of the present invention shows that the electron transfer ability is high over the entire area as compared with the comparative example. The electron transporting ability is a faster reaction nearer to 4, and the closer to 2, the slower the reaction intermediate occurs. Embodiments of the present invention are based on perovskite materials and thus exhibit excellent electron transfer capability.

Since the dual perovskite structure is capable of providing long-term stability by preventing unwanted side reactions while maintaining a perovskite structure and exhibiting excellent performance of oxygen reduction reaction and oxygen generation reaction, Can be increased, the stability can be increased, and the price can be reduced.

The dual perovskite structure can be used as an electrode material for a metal air cell, a solid oxide fuel cell, and a solid oxide electrolytic cell.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention as defined in the appended claims. Will be apparent to those of ordinary skill in the art.

1, 4: Dual Perovskite structure
2, 5: first structure, 3, 6: second structure
1000: electrospinning device, 10: spinning solution tank, 20: spinning nozzle,
30: spinning nozzle tip, 40: external power source, 50: collector substrate, 60: spinning solution,
100: metal air cell, 110: anode, 120: cathode, 130: electrolyte,
140: current collector, 142: carbon body, 144: conductive polymer material,
150: catalyst, 170: cation, 180: oxygen, 190: load,
200: solid oxide fuel cell, 210: anode,
220: cathode, 230: electrolyte, 240: buffer layer,
300: solid oxide electrolytic cell, 310: anode, 320: cathode,
330: electrolyte, 340: external power supply,

Claims (20)

A first structure including a first perovskite compound and having a cylindrical shape; And a second structure having a shape of particles formed to cover the entire surface of the first structure so that the first structure has a rough surface morphology, the second structure including a second perovskite compound, A cathode having an electrode material including a skate structure;
An anode facing the cathode; And
And an electrolyte disposed between the cathode and the anode,
Wherein the first perovskite compound is an Nd _x Sr _1-x Co _y O _{3 -δ} compound wherein x is 0.5, y is 1.1, 隆 is a positive number of 1 or less, Nd _x Sr _{1- x} Co _y O _{3 -?} compound to an electrical neutrality)
The second perovskite compound is a metal air battery, comprising a compound NdCoO _3. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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