KR20200094876A - Solid oxide fuel cells and solid oxide electrolysis cells - Google Patents

Abstract

The present invention relates to a solid oxide fuel cell and a solid oxide electrolysis cell. According to the present invention, the solid oxide fuel cell and the solid oxide electrolysis cell comprises, respectively; a flat tubular unit cell (100) having a plurality of tubular through-holes (111a, 111b) for transferring fuel gas formed in a longitudinal direction; an upper cap (200) coupled to one longitudinal end of the flat tubular unit cell (100) and blocking one end of the flat tubular unit cell (100) from the outside while communicating the plurality of tubular through-holes (111a, 111b) with each other; a cell lower slit (300) coupled to the other longitudinal end of the flat tubular unit cell (100), having an opening part (320) opening the plurality of tubular through-holes (111a, 111b) formed therein, and having an insertion groove (330) formed on a lower surface; and a manifold (400) coupled to the cell lower slit (300), having spaces (420, 430) formed therein to communicate with the plurality of tubular through-holes (111a, 111b), including a reaction gas inlet (450) through which the fuel gas is supplied and a reaction gas outlet (460) through which the fuel gas reacting with air is discharged, and dividing the spaces (420, 430) and the plurality of tubular through-holes (111) into halves to form the flow of fuel gas in a U-shape. Accordingly, since a flat tubular unit cell and a flat planar unit cell are divided into halves, respectively, inflow and outflow of the fuel gas are performed in one manifold, thereby providing advantages of increasing sealing efficiency, and increasing performance and efficiency of a fuel cell through a heat exchange function.

Description

Solid oxide fuel cell and solid oxide electrolysis cell {SOLID OXIDE FUEL CELLS AND SOLID OXIDE ELECTROLYSIS CELLS}

The present invention relates to a solid oxide fuel cell and a solid oxide electrolytic cell, and more particularly, to a solid oxide fuel cell and a solid oxide electrolytic cell for improving performance and efficiency.

Solid Oxide Fuel Cells (SOFCs) and Solid Oxide Electrolysis Cells (SOECs) are composed of ceramics with excellent heat resistance, both of which are the basic elements of the cell, the electrolyte membrane and electrodes.

Solid oxide fuel cells are known as fuel cells that operate in a relatively wide temperature range compared to other fuel cells, and are being developed as power generation devices for home or small-scale residential complexes and transportation as well as large-scale distributed power generation.

The solid oxide electrolysis cell can be used as a high-temperature electrolysis device that produces hydrogen from steam through the reverse reaction process of a fuel cell, and in the United States, a high-temperature electrolysis hydrogen production technology using nuclear power in connection with a very high temperature reactor (VHTR) is used. It is under development and has demonstrated hydrogen production by developing a stack-scale high-temperature electrolysis hydrogen production system in Korea.

In recent years, solid oxide fuel cells have been reversely reacted with an electrolysis device instead of electricity production.In particular, using an electrolysis cell, which is a reverse reaction device, is used to electrolyze greenhouse gases and carbon dioxide, which are the main causes of global warming, together with steam to produce syngas. It is attracting attention as a means of energy storage and greenhouse gas recycling to produce and convert to various liquid fuels such as methanol and gasoline.

Liquid fuel such as gasoline produced through high-temperature electrolysis of water and carbon dioxide can be used as fuel for transportation means such as buses, aircraft, and ships, so the existing infrastructure can be used as it is. Unlike alternative energy, it has the advantage of not having to build a new type of infrastructure. In addition, through hydrogen production using high-temperature electrolysis, low-quality new and renewable energy intermittently produced and surplus power of the system can be stored as hydrogen energy. When power is needed, power is produced by consuming hydrogen using a solid oxide fuel cell. As this is possible, it is possible to maximize the use of power storage and power facilities.

A single cell, which is a core component of a solid oxide electrolytic cell and a fuel cell, is composed of an electrolyte membrane having oxygen ion conductivity and an anode and a cathode on both sides thereof. In the case of a solid oxide electrolysis cell, when hot steam is supplied to the anode and electricity is applied, water is electrolyzed to generate hydrogen and oxygen ions, and oxygen ions move to the cathode through the electrolyte membrane, so pure oxygen and hydrogen are separated and generated. do. In the case of a solid oxide fuel cell, when oxygen and fuel are supplied to the cathode and anode respectively, oxygen reduction reaction occurs at the cathode and oxygen ions are generated and move to the anode through the electrolyte membrane, and at the anode, the fuel reacts with oxygen ions and is oxidized to water. As a result, electrons are generated to produce electricity.

Solid oxide electrolytic cells and fuel cells can be classified into three types: tube (cylindrical) type, flat tube type, and flat plate type, depending on the shape of the cell, and composed of an anode and an anode on both sides of the electrolyte membrane to form a unit cell. , According to the components that play the role of a support, it is classified into an anode support type, an electrolyte membrane support type, and a metal support type.

The solid oxide electrolytic cell and fuel cell having a dual anode support structure are in the form of a very thin (10~30μm) electrolyte membrane coated on the anode support, and at a lower temperature (700~800℃) than the previous electrolyte membrane support structure. Operation is possible. In fact, the solid oxide electrolytic cell and the fuel cell are operated as a stack by stacking several unit cells in order to obtain a desired electrolysis capability and electrical output. When a flat solid oxide electrolytic cell and a fuel cell are stacked to form a stack, a separator, which is an interconnect that provides electrical contact by connecting the anode of one cell and the cathode of another adjacent cell, is required.

In addition to the function of providing electrical contact, the separator also distributes fuel and air supplied to the anode and cathode evenly on the cell surface, prevents gas from the anode and cathode from mixing, and prevents the supplied fuel and air from being mixed with each other. It serves to provide a sealing area to prevent spillage into the furnace. Metal and ceramic materials are used for the separator. A metal separator that is easy to manufacture and mechanically process in a large area is easy, but the ceramic connector and separator with oxidation resistance have high conductivity in terms of long-term performance. Ceramic separators or connectors have excellent properties.

When a unit cell is manufactured as a stack, the manifold of the separator provides a flow path through which reaction gas is supplied and generated gas is discharged. Since the uniform supply of gas supplied to the unit cell during stack operation has a very important effect on the operating performance of the electrolytic cell and the fuel cell, many studies are being conducted on the structure and arrangement of the manifold.

Therefore, in order to manufacture a high-performance solid oxide electrolytic cell and a fuel cell stack, a fuel flow path and an air flow path are formed for each unit cell connected in series or in parallel, so that the fuel and air independently circulate through each flow path. The flow path of the manifold and connecting material (or separator) must be well designed and processed to ensure uniform supply of the manifold.

The stack is divided into an internal manifold stack and an external manifold stack according to the position of the manifold, and the flow path of the separator can be largely divided into counter flow, co-flow, and cross flow. have. For example, in the case of a separating plate having various types of flow paths, gases from the manifold are distributed along a horizontal main channel and a microchannel in a vertical direction to the main channel, and the opposite side of the separation plate is in a vertical direction. The gas passage is processed and finally the two gases flow in a direction perpendicular to each other. The supplied gas is distributed in the main flow path on the inlet manifold side according to the shape and differential pressure of the micro-channels, is supplied to the micro-channels, is recombined at the outlet side, and discharged to the outside of the stack.

In particular, when the fuel and air supplied to the anode and the cathode are supplied to the separation plate through the manifold, when the fuel and air are mixed in the stack and directly contact them, a combustion reaction may occur and damage to the anode may occur. In addition, when the supplied fuel and air flow out of the stack, the performance of the electrolytic cell and the fuel cell deteriorates, and the amount of supplied fuel and air increases, thereby reducing the efficiency. Therefore, maintaining a good seal between the manifold and the unit cell (or connector/separator) is important to the performance of the electrolytic cell and fuel cell in order to prevent direct contact between fuel and air and gases inside the stack from leaking out of the stack. Will have an effect.

Therefore, when a solid oxide fuel cell and an electrolytic cell are stacked to form a stack, a glass sealing material is mainly used to maintain the sealing between the unit cell and the manifold. Solid oxide electrolytic cells and fuel cells are operated at a high temperature of 600 to 1000 ℃, and as the height of the stack increases, a temperature difference may occur between the upper and lower portions of the stack. Load by In addition, due to periodic operation and stopping, the glass sealant is broken due to thermal shock generated by repeated cooling and heating, resulting in a problem that the sealing is deteriorated.

For this reason, a tube type rather than a flat tube type or a flat tube type, which is a structure in which the contact area is increased by slightly increasing the contact area, is proposed as a structure that minimizes the stress area caused by thermal expansion, and accordingly, the flat tube type SOFC or SOEC stack module is the most thermal. It is considered to be the most optimized structure capable of repetitive operation (heat cycle operation) from room temperature to high temperature by minimizing stress.

However, in the flat tubular solid oxide fuel cell and the electrolytic cell, ceramic, that is, a glass sealant must be used for the part connecting the manifold and the unit cell, but this part is a vulnerable part where fuel gas or hydrogen gas may leak. In particular, during thermal cycle operation in which the fuel cell is operated while changing the reaction temperature and room temperature, the gas sealing is broken due to such a weak area, that is, the area where the sealing material is used, and thus gas leakage may occur frequently.

In a general tube-type or flat-tubular cell, in a structure in which two manifolds are placed, one on each side of the cell in the stack, especially when the cell undergoes oxidation and reduction due to thermal cycle operation, a volume change is accompanied and different cells are placed in two places. Since it is fixed to the manifold with a sealing material, it is impossible to overcome the difference in volume or length change, which generates a considerably large stress. If this value exceeds the limit, cracks occur in the mechanically weak areas and the material breaks down. Therefore, as hydrogen leakage occurs, performance degradation and corrosion can occur very rapidly.

It is an object of the present invention to apply a one-way manifold and configure a single cell or stack module to have a U-shaped fuel gas flow to increase sealing efficiency, prevent gas leakage, and effectively improve gas distribution to reduce energy loss, reduce electrical output performance, and The present invention relates to a solid oxide fuel cell and a solid oxide electrolysis cell to improve efficiency.

According to the features of the present invention for achieving the object as described above, the present invention is coupled to a flat tubular unit cell in which a plurality of tubular through holes are formed for fuel gas movement in the longitudinal direction and one end in the longitudinal direction of the flat tubular unit cell, An upper cap that shields one end of the flat tubular unit cell from the outside while communicating the plurality of tubular through-holes with the outside and the other end in the longitudinal direction of the flat tubular unit cell, and an opening for opening the plurality of tubular through-holes is formed on the bottom surface. A reaction gas that is combined with the lower cell slit and the lower cell slit, where the fitting groove is formed, a space communicating with the plurality of tubular through-holes is formed, and the fuel gas inlet into which the fuel gas is injected and the gas reacted with the air by the fuel gas is discharged. An outlet is provided, and includes a manifold for dividing the space and a plurality of tubular through holes in half to form a flow of fuel gas in a U shape.

The manifold is coupled to the fitting groove of the cell lower slit when the manifold is coupled to the cell lower slit, and divides the space and the plurality of tubular through holes into halves, and a first space communicating with the halves of the plurality of tubular through holes and the plurality of And a diaphragm defining a second space communicating with the other half of the tubular through-hole, wherein the fuel gas inlet communicates with the first space, and the gas outlet communicates with the second space.

The manifold is combined with a cell lower slit of a unit cell module formed by coupling the upper cap to one end of the flat tubular unit cell and the cell lower slit to the other end to form a flow of fuel gas in a U shape, or Combined with the cell lower slits of the stack module formed by connecting a plurality of flat tubular unit cell modules formed by combining the upper cap to one end of the flat tubular unit cell and the cell lower slits to the other end to prevent the flow of fuel gas. It is formed in a U shape.

In the stack module, the flat tubular unit cell modules are connected via a cell-to-cell connector, a negative electrode plate and a positive plate are further connected to each other through a cell-cell connection material on both sides of the stack module, and a negative terminal (-electrode part) is provided on one negative plate and the positive plate. A positive terminal (+ electrode part) is provided on the other negative electrode plate and the positive electrode plate opposite to each other.

The inter-cell connector is formed of one selected from a porous current collector and a current collector mesh, or a combination thereof so as to allow air inflow while filling the space between the flat tubular unit cells.

The flat tubular unit cell has a plurality of tubular through-holes formed therein, the anode and the support, a flat tubular support, an electrolyte membrane coated to cover a portion of one and both sides and the other surface of the flat tubular support, and the other surface opposite the flat tubular support. It includes a ceramic connector coated on a portion where the flat tubular support is exposed, and a cathode coated on the electrolyte membrane.

The flat tubular support includes Ni0-YSZ, the electrolyte membrane includes YSZ,

The ceramic connector includes LST and LSF, and the cathode includes GDC, LSCF-GDC, and LSC.

The upper cap and the lower slit of the cell are coupled to the flat tubular unit cell and attached with a sealing glass.

The fuel gas contains hydrogen.

In the longitudinal direction, one end is shielded and a number of tubular through holes are formed at the opposite end, and the middle part communicates with a plurality of tubular through holes, and at the same time, a flow path that divides the plurality of tubular through holes in half to form a U-shaped flow of fuel gas is formed. In the other end, a flat unit cell having a fitting groove formed at a position dividing the plurality of tubular through holes in half and the flat unit cell are combined, a space communicating with the plurality of tubular through holes is formed, and fuel gas is injected. A fuel gas inlet and a reaction gas outlet through which the fuel gas is discharged are provided, and a manifold for dividing the space and a plurality of tubular through holes in half to form a flow of fuel gas in a U-shape.

The manifold is coupled to the fitting groove of the unit cell when the manifold is coupled to the flat unit cell, and divides the space and the plurality of tubular through holes into halves and communicates with the plurality of tubular through holes. And a diaphragm defining a second space communicating with the other half of the tubular through-hole, wherein the fuel gas inlet communicates with the first space, and the gas outlet communicates with the second space.

The manifold is combined with the other end of the flat unit cell to form a U-shaped flow of fuel gas, or is combined with the other ends of the stack module formed by combining a plurality of flat unit cells to reduce the flow of fuel gas. Form in a shape

In the stack module, the flat unit cell modules are coupled via a cell-to-cell connector, a negative electrode plate and a positive plate are further coupled to each other through a cell-cell connection material on both sides of the stack module, and a negative terminal (-electrode) is provided on one negative plate and the positive plate. A positive terminal (+ electrode part) is provided on the other negative electrode plate and the positive electrode plate opposite to each other.

The inter-cell connection material is formed of one selected from a porous current collector and a current collector mesh, or a combination thereof so as to allow air inflow while filling the space between the flat unit cells.

The flat unit cell is shielded at one end in the longitudinal direction and a plurality of tubular through holes are formed at the opposite end, and the middle part is penetrated in the thickness direction, and the plurality of tubular through holes are divided in half in the middle part to control the flow of fuel gas. An intermediate plate provided with a separating bar forming a U-shaped flow path portion, and a first plate-shaped support body that is an anode, and an electrolyte membrane coated on the first flat-type support body, and the intermediate plate is attached to one surface of the intermediate plate to cover the flow path portion. And a second plate-shaped support attached to cover the flow path on the other surface opposite to the air electrode coated on the electrolyte membrane and the intermediate plate, and a ceramic connector coated on the second plate-shaped support.

The intermediate plate is made of metal or ceramic.

The present invention uses a flat tubular unit cell or a flat unit cell, applies a manifold only in one direction, and configures a unit cell module or a stack module to have a U-shaped fuel gas flow.

The U-shaped fuel gas flow has the effect of maximizing the utilization rate of fuel gas or air by maximizing the surface area so that the fuel gas or outside air can react while flowing through a long path.

In particular, the manifold divides half of the flat tube-type unit cell and the flat-type unit cell so that the inflow and discharge of fuel gas are performed in one manifold, so that the sealing efficiency can be improved, and the inflow and discharge of fuel gas are performed in one manifold. Therefore, it is possible to increase the stability of the stack module by fixing only the part where the manifold and unit cells are connected by welding and sealing material, and it has the function of heat exchange between the incoming fuel gas and the discharged high-temperature reaction gas. There is an effect that can improve the performance and efficiency of.

1 is a cross-sectional perspective view showing a flat tubular unit cell according to an embodiment of the present invention.
2 is a view for explaining a manufacturing process of the flat tubular unit cell according to an embodiment of the present invention.
3A is a front view showing a state in which a unit cell module is formed by combining an upper cap to one end of a flat tubular unit cell and a lower slit of the cell to the other end according to an embodiment of the present invention.
Figure 3b is a cross-sectional view of Figure 3a.
Fig. 3c is a bottom view of Fig. 3a in the direction A;
Figure 4 is a cross-sectional view showing a state in which the manifold is coupled to the unit cell module of Figure 3a.
FIG. 5 is a view showing a state in which a stack module is formed by stacking a plurality of unit cell modules of FIG. 3A from the direction A of FIG. 4.
Figure 6 is a front view showing an intermediate plate in another embodiment of the present invention.
7A is a diagram illustrating a process of manufacturing a flat unit cell by applying the intermediate plate of FIG. 6.
FIG. 7B is a view showing a flat unit cell manufactured by applying the intermediate plate of FIG. 6 in a direction A of FIG. 6.
7C is a view showing a state in which a flat unit cell manufactured by applying the intermediate plate of FIG. 6 is cut in the BB direction of FIG. 6.
FIG. 7D is a view showing a state in which a flat unit cell manufactured by applying the intermediate plate of FIG. 6 is cut in the CC direction of FIG. 6.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The solid oxide fuel cell and the solid oxide electrolysis cell of the present invention use a flat tubular unit cell or a flat unit cell, apply a manifold in only one direction, and configure a unit cell module or a stack module to have a U-shaped fuel gas flow. The U-shape also includes an inverted U-shape.

For convenience of explanation, a solid oxide fuel cell using a flat tubular unit cell, a solid oxide electrolysis cell, and a solid oxide fuel cell using a flat unit cell, and a solid oxide electrolysis cell will be described.

[One Example]

In an embodiment, a single cell module or a stack module may be configured using a flat tubular unit cell.

As shown in Figure 1, the flat tubular unit cell 100 is formed with a plurality of tubular through-holes 111 for fuel gas movement in the longitudinal direction. The flat tubular unit cell 100 includes a flat tubular support 110, an electrolyte membrane 120, a ceramic connector 130, and a cathode 140. The fuel gas will be described using hydrogen gas as an example.

The flat tubular support 110 is both an anode and a support. The flat tubular support 110 may be a porous ceramic support made of Ni0-YSZ. The porous ceramic of the anode, which is a support, allows gas to move, oxygen ions, and electrons, respectively. The flat tubular support 110 is formed in a rectangular parallelepiped shape having a predetermined length and thickness. The flat tubular support 110 is formed with a plurality of tubular through holes 111 for fuel gas movement in the longitudinal direction. The tubular through-hole 111 maximizes a surface area so that fuel gas or outside air can react while flowing through a long path to maximize the utilization rate of fuel gas or air.

The tubular through hole 111 may have a circular or rectangular cross section. For example, the flat tubular support may have a length of about 200 mm, a width of about 40 mm, and a thickness of about 5 mm. The tubular through-holes 111 have a square cross section of about 2.8 mm, and 12 may be formed by 6 to the left and 6 to the right. In the embodiment, the tubular through-hole 111 has a square cross-section of about 2.8 mm, and is shown as an example that is formed to have three to the left and three to the right.

The electrolyte membrane 120 is coated to cover one side and both sides of the flat tubular support 110 and a part of the other side opposite to the one side, and the other side of the flat tubular support 110 corresponding to the opposite side coated with the electrolyte membrane 120 A flat tubular unit consisting of a cathode/electrolyte membrane/flat tubular support/ceramic connector by coating the ceramic connector 130 on the exposed portion of the flat tubular support 110 and coating the cathode 140 on the electrolyte membrane 120 The cell 100 can be manufactured. The ceramic connector 130 is coated on a portion where the flat tubular support 110 is exposed to be connected to the electrolyte membrane 120 or coated with a larger area than the exposed portion on the portion where the flat tubular support 110 is exposed to increase sealing efficiency. Can be.

The cathode 140 is coated on one side of the electrolyte membrane 120 with a width narrower than the width of one side of the flat tubular support 110. Preferably, the cathode 140 is coated on one surface of the electrolyte membrane 120 to have a width corresponding to that of the ceramic connector 130. If the cathode 140 is coated on the electrolyte membrane 120 to have the same width as the width of the flat tubular support 110, there is a concern that a short circuit may occur due to contact with a metal part when used on the cathode side manifold when manufacturing the stack (module). Accordingly, as shown in FIG. 1, the cathode 140 is coated on one side of the electrolyte membrane 120 with a width and length narrower than the width and length of one side of the flat tubular support 110.

The electrolyte membrane 120 coated to cover one side and both sides of the flat tubular support 110 and a portion of the other side opposite to one side serves to seal the flat tubular unit cell 100 so that gas leakage does not occur at both ends in the width direction. .

The flat tubular support 110 is made of Ni0-YSZ, the electrolyte membrane 120 is YSZ, the ceramic connector 130 is LST and LSF, and the air electrode 140 is made of GDC, LSCF-GDC, and LSC.

YSZ is zirconia-based ceramics (yttria stabilized zirconia), LST and LSF are lanthanum-based perovskite, and LSCF is lanthanum strontium cobalt iron composite oxide.

Specifically, YSZ is ZrO ₂ -8 molY ₂ O ₃ . NiO-YSZ is a composite of NiO and YSZ, and NiO and YSZ can have a composition of 0.1≤x≤0.9 by weight ratio, and of them, have the best characteristics in a composition of 1:1 by weight ratio.

LST is La _x Sr _1-x TiO ₃ (0.1≤x≤0.9), and the performance is the best in Example x=0.3. LSF is La _x Sr _1-x FeO ₃ (0.1≦ _x ≦0.9), and the performance is the best in Example x=0.6.

LSC is La _x Sr _1-x CoO ₃ (0.1≤x≤0.9), and the performance is the best in Example x=0.6. LSCF is (La _x Sr _1-x)( C _oy Fe _1-y) O ₃ (0.1≤x≤0.9, 0.1≤y≤0.9), and has the best performance in Example x=0.6, y=0.2 . GDC is (CeO ₂ -xGd ₂ O ₃ ) (1 mol%≤x≤30mol%), and the performance is best in Example x=10mol%.

The flat tubular unit cell 100 can be manufactured by the following process.

As shown in FIG. 2, first, a NiO-YSZ flat tubular support 110, which is both an anode and a support, is manufactured. In order to manufacture the NiO-YSZ flat tubular support 110, NiO and YSZ are mixed with alcohol (or water), an organic binder, and a pore former, and then extruded into a flat tubular support. After drying it, a preliminary heat treatment (pre-sintering) at a temperature of 1000° C. or higher is performed to manufacture the flat tubular support 110. For example, after sintering, the final size of the flat tubular support 110 may be 175 mm long and 55 mm wide and 5 mm thick. In the center of the flat tubular support, a plurality of circular or rectangular tubular holes are provided. In this embodiment, there are three square tubular through holes 111 of about 2.8 mm to the left and three to the right, so that all six holes are shown.

In the actually manufactured flat tubular unit cell module or stack module, three of the left side of the six tubular through holes can be used as the fuel gas inlet side, and three of the right side can be used as the reactive gas outlet side.

The flat tubular support 110, which is a porous anode and support, is manufactured by extrusion molding and sintering in a composition of NiO-YSZ (1:1), and then YSZ, an oxygen ion conductor, is attached to the flat tubular support 110. After slurry coating and drying, preliminary sintering is performed to coat the surface to a thickness of about 10 to 40 μm to form the electrolyte membrane 120.

The slurry is prepared by dissolving and dispersing about 50 g of YSZ powder in 400 cc of ethyl alcohol, 10 cc of fish oil, and PVB, an organic binder. The other surface of the flat tubular support 110 to be coated with the ceramic connector is attached with an organic material such as double-sided tape to prevent YSZ from being coated during heat treatment. Therefore, it is possible to coat the other three surfaces of the flat tubular support 110 attached with an organic material such as double-sided tape with YSZ except for the other surface. Preferably, one side and both sides of the flat tubular support 110 and a portion of the other side opposite to the side may be coated with YSZ. More preferably, the remaining surfaces of the flat tubular support 110 may be coated with YSZ except for a surface attached with an organic material such as double-sided tape.

After coating YSZ on the flat tubular support 110, heat treatment is performed again at 1250°C, which is a pre-sintering temperature. After the heat treatment, the YSZ portion is removed from the place where the double-sided tape was located, so that the surface of the NiO-YSZ flat tubular support 110 is exposed as it is.

Next, the portion where the flat tubular support 110 is exposed is coated with LST, which is a component of the ceramic connector. By increasing the viscosity of the slurry paste, a paste having an LST composition is first prepared, and then coated with a larger area than the exposed NiO-YSZ portion. In this case, a screen printing machine may be used for coating. The surface of the YSZ flat tubular support 110 is coated with an LST composition and heat-treated at 1250° C. to coat the first layer of the ceramic connector. Next, a second layer of ceramic connector is coated with the LSF composition.

After preparing a paste of the LSF composition under the same conditions as the LST composition, a dense film is prepared by screen printing on the LST composition. It is then dried and pre-sintered at 1250°C. A unit consisting of an electrolyte membrane (YSZ membrane)/flat tubular support (NiO-YSZ)/ceramic connector (LST membrane+LSF membrane) by simultaneously heat-treating (co-sintering) the pre-sintered body of the resulting cell at a high temperature of 1500℃ or higher. Build the cell. During final sintering, each component may be warped due to the difference in sintering shrinkage, so it is sintered by pressing with an alumina brick, or sintered by pressing, and the electrolyte membrane/flat support/ceramic in a flat shape as shown in Fig.2(c). A unit cell composed of a connector is manufactured.

As shown in (d) of FIG. 2, the cathode 140 is coated on the electrolyte membrane 120. The cathode 140 prints GDC as a primary cathode and heat-treats at 1250°C, and then prints the LSCF-GDC mixed cathode as a secondary cathode and heat-treats at 1100°C. Finally, after printing LSC as a tertiary cathode, about By heat treatment at 800° C., a final flat tubular unit cell 100 as shown in FIG. 2(d) is manufactured.

As shown in (e) of FIG. 2, the flat tubular unit cells 100 may be stacked with an inter-cell connector to form a stack.

The cell-to-cell connector may be formed of one selected from among a current collector layer, a porous current collector, and a current collector mesh, or a combination thereof, so as to fill the space between the flat tubular unit cells 100 and provide electrical contact and air inflow into the cathode 140. I can.

In the embodiment, the cell-to-cell connector includes a current collector layer 150 attached or coated on the cathode 140 and a current collector 160 mounted on the current collector layer 150, and the current collector 160 and the ceramic connector 130 ) By attaching or applying the current collecting layer 150 between them to improve the current collecting efficiency. The current collecting layer 150 may be formed of LSM, LSF, LSC, Ag (silver paste), or the like.

The current collector 160 forms a flow path through which air is introduced into the cathode 140. The current collector 160 is illustrated in a pleated or mesh form.

As shown in FIG. 3A, a unit cell module may be formed by combining the upper cap 200 at one end of the flat tubular unit cell 100 and the lower slit 300 at the opposite end of the cell.

In the drawing, in the flat tubular unit cell 100, one end becomes the upper side and the other end becomes the lower side.

The upper cap 200 is formed in a square cap shape corresponding to one end of the flat tubular unit cell 100. The upper cap 200 is coupled to one end in the longitudinal direction of the flat tubular unit cell 100 and shields one end of the flat tubular unit cell 100 from the outside while communicating a plurality of tubular through holes 111 with each other. That is, the upper cap 200 serves as a stopper blocking the upper side of the flat tubular unit cell 100 and a space for communicating a plurality of tubular through holes 111a and 111b on the upper side of the flat tubular unit cell 100 Form 210.

3B and 3C, the cell lower slit 300 is coupled to the other end of the flat tubular unit cell 100 in the longitudinal direction. The cell lower slit 300 has an opening 320 for opening a plurality of tubular through holes 111. In the lower cell slit 300, a fitting groove 330 is formed at a position that divides half at the bottom edge. A diaphragm, which will be described later, is inserted into the fitting groove 330 to divide a plurality of tubular through holes 111 in half. The cell lower slit 300 is for easily connecting the manifold and the flat tubular unit cell 100 to be described later. In the embodiment, the fitting groove 330 is formed in a rectangular shape at a position dividing a half from the bottom edge of the cell lower slit 300, but may be concave in a triangular shape with a pointed end.

The upper cap 200 and the lower cell slit 300 are coupled to one end and the other end of the flat tubular unit cell 100 and are sealed by attaching the coupled portion with a high-temperature sealing glass. The upper cap 200 and the lower cell slit 300 may be formed of a metal or ceramic material. The unit cell module formed by attaching the upper cap 200 and the lower cell slit 300 to the flat tubular unit cell 100 facilitates gas sealing and facilitates connection with each other.

As shown in FIG. 3B, the flat tubular unit cell 100 is wrapped with an electrolyte membrane 120 in a portion coupled to the upper cap 200 and the lower slit 300 to maintain sealing and insulating functions, and FIG. 3A And, as shown in FIG. 3C, the cathode 140 and the ceramic connector 130 do not contact the upper cap 200 and the lower slit 300 of the cell to prevent an electrical short.

As shown in FIG. 4, the manifold 400 is coupled to the slit 300 under the cell of the unit cell module. The manifold 400 is provided with spaces 420 and 430 communicating with a plurality of tubular through-holes 111, and a fuel gas inlet 450 into which fuel gas is injected and a reaction gas outlet 460 through which fuel gas is discharged. The manifold 400 divides the spaces 420 and 430 and a plurality of tubular through holes 111 in the manifold 400 in half to form a flow of fuel gas in a U shape (inverted U shape in the drawing).

In the manifold 400, the diaphragm 410 divides the spaces 420 and 430 in the manifold 400 and a plurality of tubular through holes 111 in half. The diaphragm 410 is provided in the manifold 400 and is coupled to the fitting groove 330 of the cell lower slit 300 when the manifold 400 is coupled with the cell lower slit 300 to provide spaces 420 and 430 and a plurality of tubular through holes. Divide (111a, 111b) in half.

The diaphragm 410 communicates with the spaces 420 and 430 in the manifold 400 with half of the plurality of tubular through-holes 111 (three tubular through-holes 111a on the left in the drawing) to serve as the inlet side manifold ( It is divided into a second space 430 that communicates with 420 and the other half of the plurality of tubular through holes 111 (three tubular through holes 111b on the right in the drawing) and serves as an exit manifold. The diaphragm 410 is coupled to the fitting groove 330 of the cell lower slit 300 and is in close contact with the flat tubular support 110, so that the first space 420 and the second space 430 are completely separated.

The fuel gas (hydrogen, etc.) inlet 450 communicates with the first space 420, and the gas outlet 460 communicates with the second space 430. Therefore, the fuel gas injected into the fuel gas inlet 450 moves in the direction of the upper cap 200 through the three tubular through holes 111a on the left side of the drawing through the first space 420, and the upper cap 200 The gas outlet of the second space 430 after moving in the direction of the lower cell slit 300 through the three tubular through holes 111b on the right side of the drawing and flowing into the second space 430 ( A U-shaped flow of fuel gas going out to 460 is formed. Unreacted fuel gas (hydrogen, etc.) and steam (water) are discharged through the reaction gas outlet 460.

In the solid oxide fuel cell and the solid oxide electrolytic cell, when air and fuel gas (steam vapor and hydrogen in the case of an electrolytic cell) are supplied to the cathode and the anode, respectively, oxygen reduction reaction occurs at the cathode and oxygen ions are generated and transferred to the anode through the electrolyte membrane. It moves, and in the anode, the fuel gas flowing through the tubular through-hole reacts with oxygen ions and is oxidized to steam (water) to produce electricity. The high-temperature steam and unreacted hydrogen generated in the reaction process are discharged through the reaction gas outlet 460.

In the case of the electrolytic cell, steam vapor and hydrogen are injected into the fuel gas side, and the steam is decomposed from the anode into hydrogen and oxygen by the electric energy applied from the outside, and the decomposed oxygen is ionized and passed through the electrolyte membrane to reach the opposite cathode. Then, it is converted back to oxygen gas, and hydrogen and oxygen are produced in the respective anode and cathode. Likewise, the oxygen gas generated by reaction is discharged from the cathode to the outside, and the high-temperature unreacted steam and generated hydrogen gas are discharged from the anode through the reaction gas outlet.

As shown in Figure 4, the manifold 400 is formed by combining the upper cap 200 to one end of the flat tubular unit cell 100 and the cell lower slit 300 to the other end of the unit cell module It is combined with the slit 300 to form a flow of fuel gas in a U shape.

In addition, since the manifold 400 is applied only in one direction of the flat tubular unit cell 100, the flat tubular unit cell 100 can be freely stretched and contracted. In the case of the solid oxide fuel cell and the solid oxide electrolytic cell, if the initial reduction reaction for normal operation causes contraction in the longitudinal direction or the width direction of the flat tubular unit cell 100 and the reduction reaction ends or some oxidation reaction proceeds, the original It also returns to size, which involves a change in length of about 5-10% at each stage.

Therefore, if there are manifolds in both directions of the flat tubular unit cell, cracks are generated in the sealing portion connecting the flat tubular unit cell and the manifold by interfering with the free expansion and contraction of the flat tubular unit cell, causing gas leakage, or in severe cases, the flat tubular unit cell. It may cause damage to the flat tubular unit cell due to stress that suppresses the shrinkage, which may cause a problem in the stability of the solid oxide fuel cell and the solid oxide electrolytic cell. Specifically, in the structure of fixing the manifolds on both sides of the flat tubular unit cell, when the unit cell undergoes oxidation and reduction due to thermal cycle operation, a volume change is accompanied in each step, and different unit cells are used as a sealing material in the two manifolds. Because it is fixed, it cannot overcome the difference in volume or length, and a considerable stress occurs. If this value exceeds the limit, cracks occur in the mechanically weak areas and the material breaks down. Therefore, fuel gas leakage may occur, and performance degradation and corrosion may occur rapidly.

However, in this embodiment, since the manifold is fixed only in one direction of the flat tubular unit cell and the other is mounted freely, the disadvantage of generating stress can be eliminated.

In addition, a fuel gas inlet 450 and a reaction gas outlet 460 are formed in one manifold 400, and a plurality of tubular through holes 111 of the flat tubular support 110 are divided in half, and the fuel gas inlet 450 is divided into half. ), and the other half communicates with the reaction gas outlet 460 to form a U-shaped flow of fuel gas, so it is easy to seal, and the fuel gas flowing into the fuel gas inlet and the high-temperature fuel discharged through the reaction gas outlet By having a heat exchange function with gas (steam and hydrogen in the case of an electrolytic cell), the performance and efficiency of the fuel cell can be improved, and the thermal shock to the manifold 400 made of a metal material can be minimized to ensure stability.

In addition, since fuel gas flows through the tubular through-hole 111 of one flat tubular unit cell, it is possible to participate in the cell reaction while flowing through a relatively long path, thereby maximizing the utilization rate of fuel gas, thereby improving performance and efficiency. Can help.

In addition, the manifold 400 may be ceramic coated on a portion in contact with the lower cell slit 300 so as to be insulated from the lower cell slit 300 made of a metal material. Alternatively, the manifold 400 may be formed of a ceramic material for insulation.

The manifold 400 has a coupling slit 440 formed on the upper inner surface. The cell lower slit 300 of the unit cell module is slidingly coupled from the side to the coupling slit 440. When the unit cell module formed by coupling the upper cap 200 to one end of the flat tubular unit cell 100 to the coupling slit 440 of the manifold 400 and the cell lower slit 300 to the other end is coupled The surface is closed and sealed through sealing or the like so that only the fuel gas inlet 450 and the reaction gas outlet 460 are opened.

One cell module can be used to produce electricity (in the case of fuel cells) or to produce hydrogen by high-temperature electrolysis of steam (in the case of an electrolysis cell), but the desired electricity output or hydrogen by electrolysis of steam In order to obtain production output, a plurality of flat tubular unit cells 100 may be stacked and operated as a stack (fuel cell or electrolytic cell) module. For example, 20 unit cell modules may be stacked to form a stack (fuel cell or electrolytic cell) module.

A state in which a stack module is formed by stacking a plurality of unit cell modules is as shown in FIG. 5 when viewed from the direction A of FIG. 4.

As shown in Fig. 5, the stack module forms a flat tubular unit cell module by combining the upper cap 200 to one end of each flat tubular unit cell 100 and attaching and attaching the cell lower slit 300 to the other end. And, it can be formed by connecting a plurality of these flat tubular unit cell modules. In the embodiment, four flat tubular unit cell modules are connected as an example.

In the stack module, the flat tubular unit cell modules are connected via a connecting material between cells. The cell-to-cell connector plays a similar role to the ceramic connector 130, which serves to draw (or apply) electricity to the outside along with sealing fuel gas from the outer part of the anode of the flat tubular unit cell 100, but the difference is fuel (reaction ) It is not necessary to have airtightness of the gas, and it is located on the surface of the ceramic connector 130 and connects it to the outside, and serves to provide electrical contact by connecting the air electrodes of other neighboring flat tubular unit cells.

The cell-to-cell connector is one selected from among the current collecting layer 150, the porous current collector 160, and the current collecting mesh so as to fill the space between the flat tubular unit cells 100 and provide electrical contact and air inflow to the cathode 140 It can be formed by a combination of these.

In order to connect the flat tubular unit cells 100 well, a cell-to-cell connector is required that can sufficiently conduct electric conduction while filling the space between the flat tubular unit cells 100. The cell-to-cell connector is a porous current collector or current collector formed by coating silver or conductive ceramic paste (LSM, LSF, LSC, etc.) on a corrugated plate shape or a porous material that allows gas flow while filling the space between flat tubular unit cells. It can be a mesh.

For example, above a certain space, a corrugated plate shape is made in a shape such as gas flow and a channel, and it is filled between the flat tubular unit cells 100 to facilitate air flow, and silver or LSM in the corrugated plate shape, Conductive ceramic pastes such as LSF and LSC are coated to have oxidation resistance and high conductivity. In particular, when the space between the flat tubular unit cells 100 is relatively large, a conductive paste is coated on a sponge or urethane and connected to burn the heat-treated organic component of about 700°C to produce a porous intercell connector, thereby preventing the flow and supply of air. It is smooth, and the current generated (or applied) between the flat tubular unit cells 100 can be well conducted to the negative terminal and the positive terminal at both ends.

Since the inter-cell connector has a porous or mesh structure, air may be introduced (or discharged) into the air electrode 140 exposed to the outside by blowing air toward the inter-cell connector side using a blower or the like. The amount of air introduced (or discharged) from the solid oxide fuel cell and the solid oxide electrolytic cell into the cathode 140 is relatively insignificant compared to the fuel gas (or steam). In the solid oxide fuel cell and the solid oxide electrolysis cell, the amount of fuel gas (or steam and hydrogen) injected through the fuel gas inlet 450 has an important effect on performance and efficiency, so the air supplied to the cathode 140 is external Use air.

The anode plate and the positive plate are further connected to both sides of the stack module through the intercell connector, and the negative terminal (-electrode part) is connected to one negative plate, and the positive terminal (+ electrode part) is connected to the opposite positive plate. It is possible to manufacture batteries and solid oxide electrolytic cells.

In the solid oxide fuel cell and solid oxide electrolysis cell shown in FIG. 5, when the cathode terminal and the anode terminal are connected, hydrogen (fuel gas such as reformed gas other than hydrogen and methane gas) is supplied to the anode, and air is supplied to the cathode 140 The cell reaction is carried out.

A reduction reaction of oxygen occurs in the cathode 140 to generate oxygen ions and moves to the flat tubular support 110, which is the anode, through the electrolyte membrane, and in the flat tubular support, a reduction reaction of hydrogen and oxygen flowing through the tubular through holes occurs and is oxidized to water. Electrons are generated to produce electricity. Electrons generated in each flat tubular unit cell 100 move to the negative terminal through the cell-to-cell connector and flow to the positive electrode to generate electricity. That is, oxygen ions are electrochemically combined with hydrogen gas in the flat tubular support 110, which is an anode, to generate electricity. On the other hand, in the electrolytic cell, the reaction proceeds in the opposite direction. The steam is first decomposed at the anode side by the applied electricity to generate hydrogen, and the remaining oxygen is ionized and passed through the electrolyte, and then converted to oxygen gas at the cathode to the outside. Is discharged.

Therefore, in the case of a fuel cell, the fuel gas flows from the flat tubular unit cell 100 of FIG. 4 to the top along the left three tubular through holes, and flows from the top to the lower along the right three tubular through holes to generate electricity through a cell reaction. do. Such a battery reaction occurs simultaneously in each of the 20-stage flat-tubular single-cell modules and generates power under the same conditions when the flat-tubular single-cell modules are stacked in 20-stage, so the power generation efficiency is high. Finally, the gas collected in the second space of the manifold 400 (fuel + steam + carbon dioxide (for reformed gas), etc.) is discharged through the reaction gas outlet 460. Similarly, in the case of the electrolytic cell, steam is decomposed as the reaction proceeds in the opposite direction, and hydrogen is produced on the anode side and oxygen is produced on the cathode side and discharged.

[Other Examples]

In another embodiment, a single cell module or a stack module may be configured using a flat unit cell.

The flat unit cell 600 may be manufactured using the intermediate plate 610 shown in FIG. 6.

The intermediate plate 610 is shielded at one end in the longitudinal direction and a plurality of tubular through holes 611a and 611b are formed at the opposite end, and the intermediate part is penetrated in the thickness direction, and a plurality of tubular through holes 611a and 611b in the middle part It has a shape in which a separating bar 613 is provided to form the flow path portions 611a' and 611b' that divide the fuel gas in half and form a U-shaped flow of fuel gas.

The position of the separation bar 613 may be fixed by a thin support plate 612 connecting both sides of the intermediate plate 610. The separation bar 613 and the intermediate plate 610 have the same thickness, and the U-shaped flow path portions 611a' and 611b' are formed by the separation bar 613 in the intermediate plate 610. The separating bar 613 may form U-shaped flow path portions 611a ′ and 611b ′ in the intermediate plate 610 because the lower part is connected and the upper part is not connected.

The intermediate plate 610 has a fitting groove 617 formed at a position that divides the plurality of tubular through holes 611a and 611b in half. Although not shown in another embodiment, the diaphragm 410 of the manifold 400 shown in FIG. 4 is coupled to the fitting groove 617.

The location where the fitting groove 617 is formed and the shape of the tubular through-holes 611a and 611b can be confirmed in FIG. 7A.

The intermediate plate 610 is made of a metal material or ceramic. The intermediate plate 610 has a function of providing electrical contact and evenly distributes the fuel gas and air supplied to the anode and the cathode on the surface of the unit cell, and prevents the gases of the anode and the cathode from being mixed with each other, and the supplied fuel gas and air It acts as a seal to prevent leakage of the material to the outside.

When the intermediate plate 610 is made of a metal material, it is easy to manufacture a large area and mechanically process it, and when it is made of ceramic, it has a high conductivity and has excellent properties for a solid oxide fuel cell that is operated for a long time.

In the case of non-conductor ceramic, a porous conductor such as felt made of nickel (Ni) is inserted into the space between the intermediate plates, so that the differential pressure (flow resistance) of the fuel gas and reaction gas is not large, but the lower and upper portions of the intermediate plate are not required. The electrolyte plate (first plate type support) and the ceramic connecting plate (second plate type support) attached to each other may be electrically connected to each other.

7A and 7B, the flat unit cell 600 is attached to one surface of the intermediate plate 610 so as to cover the flow path portions 611a' and 611b', and is a first flat plate type support ( 620, the electrolyte membrane 630 coated on the first flat support 620 and the air electrode 640 coated on the electrolyte membrane 630 and the flow path portion 611a' on the other surface opposite to the intermediate plate 610, 611b'), and a ceramic connector 660 coated on the second flat support 650 and the second flat support 650 attached thereto.

The first and second planar supports 620 and 650 are composed of Ni0-YSZ or LST, the electrolyte membrane 630 is composed of YSZ, the ceramic connector 660 is composed of LST and LSF, and the cathode 640 is composed of GDC, LSCF-GDC. , LSC composition.

When the flat plate unit cell 600 is manufactured using the intermediate plate 610, the intermediate plate 610 performs a sealing function to prevent direct contact between fuel gas and air, thereby preventing gas leakage.

The plate-type unit cell 600 attaches a first plate-type support 620 coated with an electrolyte membrane 630 and an air electrode 640 on one surface of the intermediate plate 610, and the first plate-type support 620 It is formed by attaching a second flat tubular support 650 coated with a ceramic connector 660 on the other surface of the intermediate plate 610 corresponding to the attached opposite surface. The flat unit cell 600 is composed of a cathode/electrolyte membrane/first flat support/intermediate plate/second flat support/ceramic connector.

Since the intermediate plate 610 has an open middle part, the electrolyte membrane 630, the cathode 640, and the ceramic connector 660 cannot be directly coated, and since there is no anode, the electrolyte membrane 630 and the ceramic connector are A flat unit cell 600 is manufactured by applying the first flat support 620 and the second flat support 650 that can serve as a support for 660.

The flat unit cell 600 can be manufactured by the following process.

As shown in FIG. 7A, the first and second plate-shaped supports 620 and 650 having a NiO-YSZ composition or an LST composition, which are both an anode and a support as porous, are fabricated. Mixing and drying NiO and YSZ (or LST composition) including alcohol (solvent), a binder, and a pore-forming agent in order to manufacture the first and second flat support (620,650) of NiO-YSZ composition (or LST composition) After that, press compression molding or extrusion molding into the shape of the first and second flat support bodies. After drying this, the first and second plate-shaped supports 620 and 650 are manufactured by preliminary heat treatment (pre-sintering) at a temperature of 1000°C or higher. After sintering, the final sizes of the first and second plate-shaped supports 620 and 650 may be 175 mm long, 55 mm wide, and 5 mm thick. That is, two plate-shaped supports 620 and 650 having the same composition and shape are manufactured, and are described as a first plate-shaped support 620 and a second plate-shaped support 650 for classification.

The electrolyte membrane 630 is coated on one side and both sides of the first flat support 620, and a ceramic connector 660 is coated on one and both sides of the second flat support 650 and sintered to prepare separately.

Attaching the first plate-shaped support 620 coated with the electrolyte membrane 630 to one surface (the upper surface of the drawing) of the intermediate plate 610 to cover the flow path portion 611a'611b', and attaching the ceramic connector 660 The coated second flat support 650 is attached to the other surface (lower surface of the drawing) of the intermediate plate 610 to cover the flow path portions 611a'611b'.

Next, the first cathode, the second cathode, and the third cathode are respectively printed on the electrolyte membrane 630 and heat-treated to produce a final flat plate-shaped unit cell 600 in which the cathode 640 is formed. The first cathode, the second cathode, and the third cathode are coated on the electrolyte membrane 630 by printing before attaching the first plate-shaped support 620 coated with the electrolyte membrane 630 to the intermediate plate 610. I can.

In the manufacturing process of the flat unit cell 600, the electrolyte membrane 630, the ceramic connector 660, and the cathode 640 are coated on the first or second flat support 620 and 650 under the same conditions as in the embodiment. Description will be omitted.

The flat unit cell 600 is shielded at one end in the longitudinal direction, and a plurality of tubular through holes 611a and 611b are formed at the opposite end, and the middle part communicates with a plurality of tubular through holes 611a and 611b and at the same time a plurality of tubular The flow path portions 611a' and 611b' are formed by dividing the through holes 611a and 611b in half to form a U-shaped flow of the fuel gas. The flat unit cell 600 has a fitting groove 617 formed at the other end at a position that divides the plurality of tubular through holes 611a and 611b in half. In the fitting groove 617, the diaphragm 410 of the manifold 400 shown in FIG. 4 is fitted to divide a plurality of tubular through holes 611a and 611b in half to form an inlet through which fuel gas is introduced and an outlet through which reaction gas is discharged. do.

As in the exemplary embodiment, the manifold 400 is coupled to the flat unit cell 600 to form a U-shaped flow of fuel gas.

Although the drawing in which the manifold 400 is coupled to the flat unit cell 600 is not shown, when described with reference to FIG. 4, the manifold 400 is coupled to the flat unit cell 600, and a plurality of tubular through holes 611a The spaces 420 and 430 communicating with the ,611b) are formed, and a fuel gas inlet 450 into which fuel gas is injected and a gas outlet 460 through which reaction gas is discharged are provided, and spaces 420 and 430 and a flat unit cell 600 are provided. ) To form a U-shaped flow of fuel gas by dividing the plurality of tubular through-holes 611a and 611b in half.

In the flat unit cell 600, the upper cap and the lower slit of the cell are not coupled, and the protrusions on both sides of the other end of the flat unit cell 600 are directly fitted to the coupling slit 440 of the manifold 400 and fixed in a coupling manner. There is a difference from one embodiment.

The flat unit cell 600 itself forms one flat unit cell module.

A plurality of flat unit cells 600 may be stacked to form a stack module. In the stack module, protrusions on both sides of the other end of each of the flat unit cells 600 are fitted into the coupling slit 440 of the manifold 400 in a fitting manner. The portion opened for fitting of the flat unit cells 600 is sealed by combining the negative electrode plate and the positive electrode plate, and then completely sealed using laser welding, sealing material, and brazing. When a plurality of flat unit cells 600 are stacked, the stacked state may be fixed by coupling fixing pins to the fixing holes 615 at both ends. In addition, when the unit cell and the manifold are combined, the gap created by the difference in thickness between the intermediate plate and the support plate is filled with the same shape with the same material, and the entire manifold is tightly connected to the manifold to facilitate sealing.

As shown in FIG. 5 on both sides of a stack module formed by combining a plurality of flat unit cells 600 in a stacked manner, a negative electrode plate and a positive electrode plate 510 and 520 are further coupled through an inter-cell connection material, and one negative plate 510 has A solid oxide fuel cell may be manufactured by having a negative electrode terminal (-electrode part) 530 and a positive electrode terminal (+ electrode part) 540 on the opposite positive electrode plate 520.

When the intermediate plate 610 is formed of a metal material (for example, STS), the flat unit cell 600 does not cause expansion and contraction of the flat unit cell 600 in the reduction reaction for normal operation, so a more stable operation is possible. .

Looking at the flat unit cell 600 in the direction A of FIG. 6, as shown in FIG. 7B, the other end of the intermediate plate 610 protrudes more toward both sides than one end, and a tubular through hole is not formed in the protruding part. . In another embodiment, the tubular through-holes 111a and 111b are formed to communicate from the other side of the intermediate plate 610 to the flow path portions 611a ′ and 611b ′ of the intermediate portion. Portions protruding further from the other end of the intermediate plate 610 to both sides may be coupled to the coupling slit 440 of the manifold 400 by fitting.

Looking at the flat unit cell 600 cut in the direction B-B of FIG. 6, as shown in FIG. 7C, it is divided into two flow path portions 611a' and 611b' in the middle portion.

Looking at the flat-panel unit cell 600 cut in the C-C direction of FIG. 6, as shown in FIG. 7D, the upper part is blocked. In addition, in FIG. 6, it is shown that the two flow path portions 611a' and 611b' communicate with each other at the top.

Therefore, the fuel gas introduced into the left three tubular through-holes 611a of the flat unit cell 600 flows upward through the left flow passage 611a' in the middle part, and then flows upward through the right flow passage 611b'. It can be seen that a U-shaped flow discharged through the three tubular through-holes 611b on the right after flowing to the bottom through is formed.

The fuel gas has been described using hydrogen as an example, but various types of combustion reactions occurring in contact with air such as methane are applicable.

In other embodiments, the same configurations as those of the one embodiment have been omitted from the redundant description, so that one embodiment can be mixed with other embodiments.

In the above-described embodiment, by applying a manifold in one direction so that the fuel gas flow has a U-shape in the flat tubular unit cell module and the flat tubular stack module, the sealing rate is increased, and the difference between the shrinkage rate and the thermal expansion rate of the flat tubular unit cell It is possible to effectively improve gas distribution in the unit cells of the solid oxide fuel cell and the solid oxide electrolytic cell by preventing the occurrence of stress and increasing the heat exchange capability.

In addition, in another embodiment, the middle plate and the manifold in one direction are applied so that the flow of fuel gas in a U-shape is applied in the flat-type unit cell and the flat-type stack module, thereby increasing the sealing rate and forming the upper cap and the lower slit of the cell as in one embodiment. The flat panel unit cell can be directly connected to the manifold without using it, so it is easy to manufacture, and the intermediate plate made of metal has the advantage of not shrinking even during normal operation of the fuel cell.

In the above-described embodiment and the other embodiment, even when a one-way manifold is applied, the inlet through which the fuel gas is introduced and the outlet through which the reaction gas is discharged are completely separated by the diaphragm, so that the fuel gas and air are in direct contact with each other, thereby causing a combustion reaction There is no damage to the air electrode and the fuel electrode. In addition, since the sealing power is excellent, it is possible to solve the problem that the performance of the unit cell and the fuel cell is deteriorated due to the outflow of fuel gas and air into the stack.

Therefore, it is possible to increase sealing efficiency by dividing half of the flat tubular unit cell and the flat unit cell to perform the inflow and discharge of fuel gas in one manifold, and the inflow and discharge of fuel gas are performed in one manifold. The stability of the stacked module can be further improved by welding and sealing only the parts to which the unit cells are connected to be fixed.

As described above, according to the present invention, since the inflow and outflow of fuel gas is performed in one manifold by dividing half of the flat tubular unit cell and the flat unit cell, the sealing efficiency can be improved and the performance and efficiency of the fuel cell can be improved.

In the present invention, for convenience of explanation, it has been described that fuel gas is introduced and discharged from one manifold, but in reality, fuel gas is introduced from one manifold and a U-shaped flow path of a flat tubular unit cell or a flat unit cell The high temperature reaction gas that reacted with air is discharged while flowing.

In addition, when the present invention is used as an electrolytic cell, the fuel gas is steam (including hydrogen), and steam (including hydrogen) is introduced from one manifold by electrolyzing it, and the U-shaped flow path of the flat tube unit cell or the flat unit cell Hydrogen (including steam) generated by decomposition while flowing is discharged.

For reference, a sealing material that seals the portion where the upper cap and the lower slit of the cell are coupled to the flat tubular unit cell, the flat tubular unit cell, the sealant or welding that seals the portion where the lower cell slit and the manifold are coupled are not shown in the drawings. .

Further, reference numerals 510, 520, 530, and 540 denote symbols expressed when the stack module of the present invention is used as a fuel cell, and when the stack module of the present invention is used as an electrolytic cell, protection and name are applied in reverse.

The present invention can be used as one or both of a solid oxide fuel cell and a solid oxide electrolytic cell.

The present invention has been described with the best embodiments in the drawings and specifications. Here, although specific terms have been used, they are used for the purpose of describing the present invention only, and are not used to limit the scope of the present invention as defined in the claims or the claims. Therefore, the present invention will be understood by those skilled in the art that various modifications and other equivalent embodiments are possible. Therefore, the true technical scope of the present invention should be defined by the technical spirit of the appended claims.

100: flat tubular unit cell 110: flat tubular support
111,111a,111b: tubular through hole 120: electrolyte membrane
130: ceramic connector 140: air electrode
150: collector layer 160: collector
200: upper cap
300: cell lower slit 210: space
320: opening 330: fitting groove
400: manifold 410: diaphragm
420,430,: first and second space 440: coupling slit
450: fuel gas inlet 460: reactive gas outlet
510: negative plate 520: positive plate
530: negative terminal (-electrode part) 540: positive terminal (+ electrode part)
600: flat unit cell 610: middle plate
611a, 611b: tubular through hole 611a', 611b': passage
613: separation bar 612: support plate
615: fixing hole 617: fitting groove
620: first flat support 630: electrolyte membrane
640: air electrode 650: second flat support
660: ceramic connector

Claims (18)

A flat tubular unit cell having a plurality of tubular through holes for moving fuel gas in the longitudinal direction;
An upper cap coupled to one end of the flat tubular unit cell in the longitudinal direction and shielding one end of the flat tubular unit cell from the outside while communicating the plurality of tubular through holes with each other; And
A space coupled to the other end in the longitudinal direction of the unit cell and communicating with the plurality of tubular through-holes is formed, and a fuel gas inlet into which fuel gas is injected and a reaction gas outlet through which gas reacted with air is discharged, the A manifold for dividing the space and a plurality of tubular through holes in half to form a U-shaped flow of fuel gas;
Solid oxide fuel cell and solid oxide electrolysis cell comprising a. The method according to claim 1,
The manifold is
Combined with the cell lower slit of the unit cell module formed by combining the upper cap to one end of the flat tubular unit cell and the cell lower slit to the other end to form a flow of fuel gas in a U shape, or
The flow of fuel gas is combined with the cell lower slits of the stack module formed by connecting a plurality of flat tubular unit cell modules formed by coupling the upper cap to one end of the flat tubular unit cell and the cell lower slits to the other end Solid oxide fuel cell and solid oxide electrolytic cell, characterized in that to form a U-shaped. The method according to claim 1,
The manifold is
Dividing the space and the plurality of tubular through-holes in half, comprising a partition plate forming a first space serving as an inlet side manifold and a second space serving as an outlet side manifold,
The fuel gas inlet communicates with the first space, and the gas outlet communicates with the second space. The method according to claim 3,
In the stack module, the flat tubular unit cell modules are connected via a connecting material between cells,
Further connecting the negative plate and the positive plate to both sides of the stack module through an inter-cell connecting material,
A solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that a negative electrode terminal (-electrode part) is provided on one negative electrode plate and a positive electrode terminal (+ electrode part) is provided on the opposite positive electrode plate. The method according to claim 4,
The cell-to-cell connector
A solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that they are formed of one selected from among a current collector layer, a porous current collector, and a current collector mesh, or a combination thereof to allow air inflow while filling the space between the flat tubular unit cells. The method according to claim 1,
The flat tubular unit cell is
A flat tubular support having a plurality of tubular through-holes and serving as a fuel electrode and a support;
An electrolyte membrane coated to cover portions of one side, both sides, and the other side of the flat tubular support;
A ceramic connector coated on a portion of the flat tubular support to which the flat tubular support is exposed on the opposite surface of the flat tubular support; And
A cathode coated on the electrolyte membrane;
Solid oxide fuel cell and solid oxide electrolytic cell comprising a. The method according to claim 6,
The flat tubular support includes Ni0-YSZ,
The electrolyte membrane includes YSZ,
The ceramic connector includes LST and LSF,
The cathode is a solid oxide fuel cell and solid oxide electrolytic cell, characterized in that it comprises a GDC, LSCF-GDC, LSC. The method according to claim 6,
The ceramic connector is a solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that the flat tubular support is coated with a larger area than the exposed portion. The method according to claim 1,
A solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that the upper cap and the lower slit of the cell are coupled to the flat tubular unit cell and attached with a sealing glass. The method according to claim 1,
The fuel gas is a solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that containing hydrogen and steam. In the longitudinal direction, one end is shielded, and a plurality of tubular through holes are formed at the opposite end, and the middle part communicates with a plurality of tubular through holes, and at the same time, a flow path part that divides the plurality of tubular through holes in half to form a U-shaped flow of fuel gas is formed. Flat unit cell; And
Combined with the flat unit cell, a space communicating with the plurality of tubular through holes is formed, and a fuel gas inlet into which fuel gas is injected and a reaction gas outlet through which fuel gas is discharged are provided, and the space and the plurality of tubular through holes are provided. A manifold divided in half to form a U-shaped flow of fuel gas;
A solid oxide fuel cell and a solid oxide electrolytic cell comprising a. The method according to claim 11,
The manifold is
Dividing the space and the plurality of tubular through-holes in half, comprising a partition plate forming a first space serving as an inlet side manifold and a second space serving as an outlet side manifold,
The fuel gas inlet communicates with the first space, and the gas outlet communicates with the second space. The method of claim 12,
The manifold is
Combined with the other end of the flat unit cell to form a U-shaped flow of fuel gas, or
A solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that combined with the other ends of a stack module formed by combining a plurality of flat unit cells to form a flow of fuel gas in a U shape. The method according to claim 13,
In the stack module, the flat cell modules are coupled through a connecting material between cells,
A negative electrode plate and a positive electrode plate are further coupled to both sides of the stack module through an inter-cell connector,
A solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that a negative electrode terminal (-electrode part) is provided on one negative electrode plate and a positive electrode terminal (+ electrode part) is provided on the opposite positive electrode plate. The method according to claim 14,
The cell-to-cell connector
A solid oxide fuel cell and a solid oxide electrolysis cell, characterized in that they are formed of one selected from among a current collector layer, a porous current collector, and a current collector mesh, or a combination thereof to allow air inflow while filling the space between the flat unit cells. The method according to claim 11,
The flat unit cell is
A flow path that forms a U-shaped flow of fuel gas by dividing the plurality of tubular through holes in the middle part in half and forming a plurality of tubular through holes at one end in the longitudinal direction and at the opposite end in the thickness direction. An intermediate plate provided with a separating bar forming a part;
A first plate-shaped support attached to one surface of the intermediate plate to cover the flow path and serving as an anode;
An electrolyte membrane coated on the first flat support;
A cathode coated on the electrolyte membrane;
A second flat plate type support attached to the other surface opposite to the intermediate plate to cover the flow path; And
A ceramic connecting member coated on the second flat support;
A solid oxide fuel cell and a solid oxide electrolytic cell comprising a. The method according to claim 16,
The intermediate plate is a solid oxide fuel cell and a solid oxide electrolytic cell, characterized in that made of a metal material or a ceramic material. The method according to claim 16,
The first and second planar supports include Ni0-YSZ or LST,
The electrolyte membrane includes YSZ,
The ceramic connector includes LST and LSF,
The cathode is a solid oxide fuel cell and solid oxide electrolytic cell, characterized in that it comprises a GDC, LSCF-GDC, LSC.

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