Solid oxide battery

Abstract

A solid oxide battery includes a fuel electrode, an air electrode, and an electrolyte disposed between the fuel electrode and the air electrode and including a plurality of rods. At least one of the fuel electrode or the air electrode is disposed along a surface of the plurality of rods.

Description

Technical Field

[0001] The present disclosure relates to a solid oxide battery. Background Art

[0002] Solid oxide fuel cells (SOFC) and solid oxide electrolyzers (SOEC) include cells composed of air electrodes, fuel electrodes and solid electrolytes with oxygen ion conductivity, in which case the cells may be referred to as solid oxide cells. Solid oxide cells generate electrical energy by electrochemical reactions, or electrolyze water to produce hydrogen by the reverse reaction of solid oxide fuel cells. Compared with other types of fuel cells or water electrolyzers (such as phosphoric acid fuel cells (PAFC), alkaline fuel cells (AFC), polymer electrolyte membrane fuel cells (PEMFC), direct methanol fuel cells (DMFC), etc.), solid oxide cells have low overvoltages based on low activation polarization and low irreversible losses, thereby providing high efficiency. In addition, solid oxide cells can be used as carbon-based fuels or hydrocarbon-based fuels and hydrogen, so there is a wide range of fuel selection. Due to the high reaction rate at the electrode, solid oxide cells have the advantage of not requiring expensive precious metals as electrode catalysts.

[0003] Solid oxide batteries generally have a structure in which an electrolyte is provided between electrode layers (e.g., an air electrode and a fuel electrode), and a reaction that functions as a battery occurs in the electrode layers. In order for the reaction to occur efficiently in the electrode layers, gas should be able to easily enter and exit, and for this purpose, a technique of forming the electrode layers into a porous body or the like is known. Summary of the invention

[0004] Technical issues

[0005] One aspect of the present disclosure is to achieve a high reactivity solid oxide cell by providing a smooth gas flow.

[0006] Technical Solution

[0007] According to one aspect of the present disclosure, a novel structure of a solid oxide cell is proposed by way of example. The solid oxide cell includes a fuel electrode, an air electrode, and an electrolyte disposed between the fuel electrode and the air electrode and including a plurality of rods (or columns). At least one of the fuel electrode or the air electrode is disposed along the surface of the plurality of rods.

[0008] The plurality of rods may be regularly arranged in columns and rows.

[0009] The plurality of rods may include at least one rod having an aspect ratio of 2 or greater.

[0010] The electrolyte may include a substrate layer having a first surface positioned on a respective side of the fuel electrode and a second surface positioned on a respective side of the air electrode, and the plurality of rods may be disposed on at least one of the first surface or the second surface of the substrate layer.

[0011] The plurality of rods may be disposed on the first surface of the base layer, and the fuel electrode may be disposed along a surface of the base layer and surfaces of the plurality of rods.

[0012] The surface of the fuel electrode may have an irregular shape.

[0013] The fuel electrode may comprise substantially no ion conductor.

[0014] The plurality of rods may be disposed on the second surface of the base layer, and the air electrode may be disposed along a surface of the base layer and a surface of the plurality of rods.

[0015] The surface of the air electrode may have an irregular shape.

[0016] The air electrode may comprise substantially no ion conductor.

[0017] The base layer may be a ceramic sintered body, and the plurality of rods may have a single crystal structure.

[0018] The base layer and the plurality of rods may be a ceramic sintered body.

[0019] The plurality of rods may include rods having a shape of at least one of a cylinder or a triangular prism.

[0020] The plurality of rods may include a rod having a tube shape.

[0021] The plurality of rods may include a rod having a plurality of protrusions formed on a surface.

[0022] According to another aspect of the present disclosure, a solid oxide cell includes a fuel electrode, an air electrode, and an electrolyte disposed between the fuel electrode and the air electrode and including a plurality of rods having an aspect ratio of 2 or more.

[0023] According to another aspect of the present disclosure, a solid oxide cell includes an electrolyte, a fuel electrode, and an air electrode, wherein the electrolyte includes a substrate layer having a first surface and a second surface opposite to each other and a plurality of pillars protruding from at least one of the first surface or the second surface of the substrate layer. The electrolyte is disposed between the fuel electrode and the air electrode.

[0024] Advantageous Effects of the Invention

[0025] In the case of a solid oxide cell according to some example embodiments of the present disclosure, a solid oxide cell having smooth gas flow and thus excellent reactivity may be provided. Therefore, when the solid oxide cell is used as a fuel cell or a water electrolyzer, performance may be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 is a schematic cross-sectional view of a solid oxide battery according to an embodiment;

[0027] Figure 2 It is shown that it can be applied to Figure 1 A three-dimensional diagram of the electrolyte in a solid oxide battery;

[0028] Figure 3 and Figure 4 is a cross-sectional view schematically showing a solid oxide battery according to a modification;

[0029] Figure 5 and Figure 6 is a magnified view of an area of ​​a solid oxide cell;

[0030] Figure 7 An example of a method of forming a rod structure of an electrolyte is shown;

[0031] Figure 8 Another example of a method of forming a rod structure of an electrolyte is shown; and

[0032] Fig. 9 , Fig.10 , Fig.11 A. Fig.11 B and Fig.11 C shows an example of the shape of a rod structure that can be used as an electrolyte. DETAILED DESCRIPTION

[0033] Hereinafter, example embodiments of the present disclosure will be described with reference to specific example embodiments and the accompanying drawings. However, the example embodiments of the present disclosure may be illustrated in many different forms and should not be construed as being limited to the specific embodiments set forth herein. The example embodiments disclosed herein are provided to better explain the present disclosure to those skilled in the art. In the accompanying drawings, the shapes and sizes of the elements may be exaggerated for clarity, and the same reference numerals will always be used to represent the same or similar elements.

[0034] In order to clearly explain the present disclosure in the drawings, contents irrelevant to the description are omitted, the thickness of each component is magnified to clearly indicate multiple layers and multiple regions, and the same reference numerals are used to describe components having the same functions within the scope of the same concept. Throughout the specification, unless otherwise specified, when a part "includes" or "contains" a component, this indicates that other components are not excluded but may also be included.

[0035] The term "substantially the same width" as used herein means that the width may have a difference of several percent (eg, less than or equal to 5%).

[0036] Figure 1 is a schematic cross-sectional view of a solid oxide battery according to an embodiment. Figure 2 It is shown that it can be applied to Figure 1 A three-dimensional diagram of the electrolyte in a solid oxide battery.

[0037] Reference Figure 1 and Figure 2 The solid oxide cell 100 according to the embodiment includes a fuel electrode 110, an air electrode 130, and an electrolyte 120 as main components, the electrolyte 120 is provided between the fuel electrode 110 and the air electrode 130 and includes a plurality of rods (or columns) 122. At least one of the fuel electrode 110 or the air electrode 130 is formed along the surface of the plurality of rods 122, and Figure 1 An example is shown in which the fuel electrode 110 is formed along the surface of the plurality of rods 122. However, as in Figure 3 In a modification of the present invention, the air electrode 130 may be formed along the surface of the plurality of rods 122. Figure 4 In a modified example, both the fuel electrode 110 and the air electrode 130 may be formed along the surfaces of the plurality of rods 122 .

[0038] The plurality of rods 122 provided in the electrolyte 120 serve as channels through which gas can easily enter and leave, thereby improving the reactivity within the solid oxide cell 100. In addition, unlike the porous electrode in which holes are randomly formed used in conventional battery structures, since the size and shape of the holes can be effectively controlled by the structure of the rods 122 of the electrolyte 120, the reactivity can be further improved. These advantages can significantly contribute to improving the characteristics of the solid oxide cell 100. Hereinafter, the components of the solid oxide cell 100 will be described in detail, and the case where the solid oxide cell 100 is used as a fuel cell will be mainly described. However, the solid oxide cell 100 can also be used as a water electrolysis cell, and in this case, a reaction opposite to that of the fuel cell will occur in the fuel electrode 110 and the air electrode 130 of the solid oxide cell 100.

[0039] Specifically, when the solid oxide cell 100 is a fuel cell, for example, water generation due to hydrogen oxidation or an oxidation reaction of a carbon compound may occur in the fuel electrode 110, and an oxygen ion generation reaction due to oxygen decomposition may occur in the air electrode 130. When the solid oxide cell 100 is a water electrolysis cell, the opposite reaction may occur. For example, hydrogen may be generated in the fuel electrode 110 according to a reduction reaction of water, and oxygen may be generated in the air electrode 130. As another example, in the case of a fuel cell, a hydrogen decomposition (hydrogen ion generation) reaction may occur in the fuel electrode 110, and oxygen ions and hydrogen ions are combined in the air electrode 130 to generate water, and in the case of a water electrolysis cell, water decomposition (hydrogen ions and oxygen ions) may occur in the fuel electrode 110, and oxygen may be generated in the air electrode 130. In the electrolyte 120, ions may move toward the fuel electrode 110 or the air electrode 130.

[0040] In the case of the present embodiment, as described above, the fuel electrode 110 is formed along the surface of the plurality of rods 122 of the electrolyte 120, and as will be described later, the fuel electrode 110 is formed using a metal body containing an electronic conductor such as Ni, and may not substantially contain an ion conductor. This is because the plurality of rods 122 of the electrolyte 120 may function as an ion conductor.

[0041] When specifically describing the materials constituting the fuel electrode 110, the electrolyte 120, and the air electrode 130, first, the fuel electrode 110 may include an electronic conductor and an ion conductor. In this case, the fuel electrode 110 may include a metal ceramic layer, and the metal ceramic layer includes a metal-containing phase and a ceramic phase that may correspond to the electronic conductor and the ion conductor, respectively. In this case, the metal-containing phase may include a metal catalyst (such as nickel (Ni), cobalt (Co), copper (Cu), their alloys, etc.) that acts as an electronic conductor. The metal catalyst may be in a metallic state or an oxide state. In the case of the ceramic phase of the fuel electrode 110, gadolinium oxide doped ceria (GDC), samarium oxide doped ceria (SDC), ytterbium oxide doped ceria (YDC), scandium oxide stabilized zirconia (SSZ), ytterbium oxide ceria scandium stabilized zirconia (YbCSSZ), etc. may be included. On the other hand, as described above, when Figure 1 and Figure 4 When the fuel electrode 110 shown in FIG. 1 is formed along the surface of the plurality of rods 122 (eg, formed along the surface), the fuel electrode 110 may substantially not contain an ion conductor. Figure 3 In the case of the flat plate structure shown, the fuel electrode 110 may be formed using a porous body including an electron conductor and an ion conductor.

[0042] The electrolyte 120 is provided between the fuel electrode 110 and the air electrode 130. As an example of a material constituting the electrolyte 120, the electrolyte 120 may include stabilized zirconia. Specifically, the electrolyte 120 may include scandia stabilized zirconia (SSZ), yttria stabilized zirconia (YSZ), scandia ceria stabilized zirconia (SCSZ), scandia ceria yttria stabilized zirconia (SCYSZ), scandia ceria ytterbium stabilized zirconia (SCYbSZ), etc.

[0043] The air electrode 130 may include an electronically conductive material such as, for example, an electronically conductive perovskite material such as lanthanum strontium manganite (LSM). Other conductive perovskites may also be used, for example metals such as lanthanum strontium cobalt (LSC), lanthanum strontium cobalt manganese (LSCM), lanthanum strontium cobalt ferrite (LSCF), lanthanum strontium ferrite (LSF), La 0.85 Sr 0.15 Cr 0.9 Ni 0.1 O3 (LSCN) or Pt. In some embodiments, the air electrode 130 may include a mixture of an electronic conductor and an ion conductor (e.g., an ion conductive ceramic material). For example, the air electrode 130 may include about 10 wt% to about 90 wt% of an electronic conductive material (e.g., LSM, etc.) and about 10 wt% to about 90 wt% of an ion conductive material. In this case, the ion conductive material may also include a zirconium oxide-based (e.g., YSZ) material and / or a ceria-based material. Figure 3 and Figure 4 As shown, when the air electrode 130 is formed along the surface of the plurality of rods 122 (eg, formed along the surface), the air electrode 130 may substantially not include an ion conductor. Figure 1 In the case of the flat plate structure shown, the air electrode 130 may be formed using a porous body including an electron conductor and an ion conductor.

[0044] Describing the structure of the rods 122 of the electrolyte 120 in more detail, the plurality of rods 122 may be a structure in which the height (h) is longer than the diameter (d) of the bottom surface. In this case, the plurality of rods 122 may include rods having an aspect ratio greater than or equal to 2. The diameter (d) of the rods 122 may refer to the diameter of an equivalent circle when the bottom surface is not circular, and may also be the average value of the maximum diameter and the diameter in a direction perpendicular to the maximum diameter.

[0045] like Figure 2As shown, the plurality of rods 122 may be regularly arranged in columns and rows. By regularly arranging the plurality of rods 122, the flow of the gas may be smoothed, and the reaction region may be expanded within the fuel electrode 110, and further, the reaction region may be uniformly arranged throughout the solid oxide cell 100. Therefore, the electron conduction path, the ion conduction path, and the gas flow path may be uniformly controlled rather than randomly controlled, and the effective area of ​​the effective reaction region (e.g., the three-phase boundary of the electron conductor, the ion conductor, and the gas) may be increased.

[0046] The electrolyte 120 includes a base layer 121 having a first surface S1 positioned on the fuel electrode 110 side and a second surface S2 positioned on the air electrode 130 side, and in this case, a plurality of rods 122 may be provided on at least one of the first surface S1 or the second surface S2 of the base layer 121. In this case, as in Figure 2 In the embodiment of the present invention, the plurality of rods 122 are disposed on the first surface S1 of the substrate layer 121, and the fuel electrode 110 may be formed along the surface of the substrate layer 121 and the surfaces of the plurality of rods 122. Figure 3 In the embodiment of the present invention, the plurality of rods 122 may be disposed on the second surface S2 of the base layer 121, and the air electrode 130 may be formed along the surface of the base layer 121 and the surface of the plurality of rods 122. Figure 4 In the embodiment, the plurality of rods 122 are disposed on both the first surface S1 and the second surface S2 of the base layer 121 , and the fuel electrode 110 and the air electrode 130 may be formed along the surface of the base layer 121 and the surfaces of the plurality of rods 122 .

[0047] On the other hand, in the case where the plurality of rods 122 include rods having an aspect ratio of 2 or more to sufficiently provide gas flow channels and reaction regions, the electrode layers 110 and 130 do not necessarily have to be formed along the surfaces of the plurality of rods 122. For example, when the electrolyte 120 includes the plurality of rods 122 having an aspect ratio of 2 or more, it is sufficient that the fuel electrode 110 or the air electrode 130 is in contact with at least a portion of the electrolyte 120, and the fuel electrode 110 or the air electrode 130 will not necessarily be formed along the surfaces of the plurality of rods 122.

[0048] The fuel electrode 110 may be formed by a method of applying a paste to the surfaces of the plurality of rods 122 and then sintering it, a method of depositing or sputtering a material of the fuel electrode 110 on the surfaces of the plurality of rods 122, or the like. When the fuel electrode 110 is formed along the surfaces of the plurality of rods 122, as in Figure 5As can be seen in the enlarged view of , the surface of the fuel electrode 110 may have an irregular shape, and a plurality of holes H1 may be provided in the surface of the fuel electrode 110. Similarly, the air electrode 130 may be formed by a method of applying a paste to the surface of the plurality of rods 122 and then sintering it, a method of depositing or sputtering a material of the air electrode 130 on the surface of the plurality of rods 122, or the like. When the air electrode 130 is formed along the surface of the plurality of rods 122, as in Figure 6 As can be seen in the enlarged view of , the surface of the air electrode 130 may include an irregular shape, and a plurality of holes H2 may be provided in the surface of the air electrode 130. In one embodiment, some portions of the fuel electrode 110 or the air electrode 130 may not contact the corresponding surfaces of the plurality of rods 122 due to the holes H1 or H2.

[0049] The rods 122 of the electrolyte 120 may be formed as follows. Figure 7 The plurality of rods 122 may be formed in the form shown on the surface of the base layer 121. In this case, a deposition process (as a specific example, metal organic chemical vapor deposition (MOCVD)) may be used to form the plurality of rods 122. When formed by such a deposition process, the base layer 121 and the plurality of rods 122 may have different organizational structures. For example, the plurality of rods 122 may have a single crystal structure, and unlike this, the base layer 121 may be a ceramic sintered body. In addition, as Figure 8 As shown, the plurality of rods 122 may be formed by etching the base layer 121. In this case, the etching process of the base layer 121 may be, for example, reactive ion etching (RIE), plasma etching, chemical etching, etc. In this way, when the plurality of rods 122 are formed by the etching process, the base layer 121 and the plurality of rods 122 may have the same organizational structure. Specifically, the base layer 121 and the plurality of rods 122 may be a ceramic sintered body.

[0050] As described above, the electrolyte 120 can provide a channel suitable for gas flow by having a plurality of rods 122, and further, can provide a wide and uniform reflection area with the electrode layers 110 and 130 connected to the plurality of rods 122. In the case of these plurality of rods 122, the shape can be variously modified as long as the rod structure is maintained. First, as Figure 2 As shown, the plurality of rods 122 may include rods having a cylindrical shape or a shape similar to a cylindrical shape, and in this case, the cylindrical shape may include a case where the shape or diameter of the bottom surface is slightly different from the shape or diameter of the upper surface. In addition to the cylindrical shape, a rod having a cylindrical shape or a cylindrical shape may also be used. Fig. 9 The rod 122 shown is in the form of a triangular prism. Further, the rod 122 may have a Fig.10 For example, the rod 122 may include a through hole H extending in the thickness direction. When the rod 122 is implemented as a tube shape in this way, the gas flow path and the reaction area can be further increased. In this case, as shown in FIG. Fig.10 As shown on the right side of FIG. 1 , the electrode layers 110 and 130 may also be formed in the through hole H of the tube-shaped rod 122. Next, as shown in FIG. Fig.11 As shown in A, the plurality of rods 122 may include rods having a plurality of protrusions P formed on the surface thereof, and the reactivity of the electrode layers 110 and 130 may be further improved by the protrusions P. The protrusions P may also be applied to Fig.11 The rod of the tube structure shown in B and Fig.11 C is a triangular prism shaped rod.

[0051] As described above, according to the example, a solid oxide cell having a smooth gas flow and thus excellent reactivity can be provided. Therefore, when the solid oxide cell is used as a fuel cell or a water electrolyzer, the performance can be improved.

[0052] While example embodiments have been shown and described above, it will be readily apparent to those skilled in the art that modifications and variations may be made without departing from the scope of the present disclosure as defined by the appended claims.

Claims

1. A solid oxide battery comprising: Fuel electrode; Air electrode; as well as an electrolyte disposed between the fuel electrode and the air electrode and comprising a plurality of rods, Wherein, at least one of the fuel electrode or the air electrode is disposed along the surface of the plurality of rods.

2. The solid oxide battery according to claim 1, wherein: The plurality of rods are regularly arranged in columns and rows.

3. The solid oxide battery according to claim 1, wherein: The plurality of rods includes at least one rod having an aspect ratio greater than or equal to 2.

4. The solid oxide battery according to claim 1, wherein: The electrolyte includes a substrate layer having a first surface positioned on a respective side of the fuel electrode and a second surface positioned on a respective side of the air electrode, and the plurality of rods are disposed on at least one of the first surface or the second surface of the substrate layer.

5. The solid oxide battery according to claim 4, wherein: The plurality of rods are disposed on the first surface of the base layer, and the fuel electrode is disposed along a surface of the base layer and surfaces of the plurality of rods.

6. The solid oxide battery according to claim 5, wherein: The surface of the fuel electrode has an irregular shape.

7. The solid oxide battery according to claim 5, wherein: The fuel electrode does not include an ion conductor.

8. The solid oxide battery according to claim 4, wherein: The plurality of rods are disposed on the second surface of the base layer, and the air electrode is disposed along a surface of the base layer and a surface of the plurality of rods.

9. The solid oxide battery according to claim 8, wherein: The surface of the air electrode has an irregular shape.

10. The solid oxide battery according to claim 8, wherein: The air electrode does not include an ion conductor.

11. The solid oxide battery according to claim 4, wherein: The base layer is a ceramic sintered body, and the plurality of rods have a single crystal structure.

12. The solid oxide battery according to claim 4, wherein: The base layer and the plurality of rods are ceramic sintered bodies.

13. The solid oxide battery according to claim 1, wherein: The plurality of rods include rods having a shape of at least one of a cylinder or a triangular prism.

14. The solid oxide battery according to claim 1, wherein: The plurality of rods include a rod having a tube shape.

15. The solid oxide battery according to claim 1, wherein: The plurality of rods include a rod having a plurality of protrusions formed on a surface thereof.

16. A solid oxide battery comprising: Fuel electrode; Air electrode; as well as The electrolyte is disposed between the fuel electrode and the air electrode and includes a plurality of rods having an aspect ratio of 2 or more.

17. The solid oxide battery according to claim 16, wherein: The plurality of rods are regularly arranged in columns and rows.

18. A solid oxide battery comprising: an electrolyte including a substrate layer having a first surface and a second surface opposite to each other, the electrolyte further comprising a plurality of pillars protruding from at least one of the first surface or the second surface of the substrate layer; Fuel electrode; as well as Air electrode, Wherein, the electrolyte is arranged between the fuel electrode and the air electrode.

19. The solid oxide battery according to claim 18, wherein: The plurality of pillars include at least one pillar having an aspect ratio greater than or equal to 2.

20. The solid oxide battery according to claim 18, wherein: Each of the plurality of pillars is in the form of a cylindrical shape, a triangular prism, or a tube shape including a through hole.

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