JP7770684B2 - Thin-film solid oxide fuel cell package with stack structure - Google Patents

Description

The present invention relates to a thin-film solid oxide fuel cell package having a stack structure.

A solid oxide fuel cell (SOFC) is a type of highly efficient energy conversion device that converts chemical energy into electrical energy. It is a fuel cell that uses a solid oxide membrane as an electrolyte.

YSZ (Yttrium Stabilized Zirconia) is the main electrolyte used in SOFC electrolyte membranes, and thin-film SOFCs manufactured using a micro-electro-mechanical system (MEMS) process have a membrane structure that is post-etched, with the electrolyte membrane and electrodes formed on a silicon substrate using a free-standing method (see, for example, Patent Document 1).

Here, due to the effective microstructure, the electrolyte can be reduced in thickness to reduce resistance and thereby offset ionic conduction at low temperatures, and the electrodes can be nanostructured to increase the specific surface area, thereby offsetting low activation at low temperatures by increasing the density of reaction sites.

In order for a stack of unit cells housed in a designated package to function as a fuel cell, the inside of the stack must be sealed so that the fuel is separated from oxygen (air).

In the case of polymer fuel cells, it is possible to seal the fuel flow path using bolts and gaskets, but in the case of small and lightweight thin-film solid oxide fuel cells, it is not easy to seal the inside of the stack due to the limitations of the membrane structure, in which the electrolyte film and electrodes are formed on a silicon substrate using a free-standing method.

Japanese Patent Publication No. 4914831

The present invention was made in consideration of the above, and one of its objects is to provide a thin-film solid oxide fuel cell package having a stack structure.

Another object is to provide a solid oxide fuel cell including a thin-film solid oxide fuel cell package having a stack structure.

The problems solved by the present invention are not limited to those mentioned above, and other problems not mentioned will be clearly understood by those with ordinary skill in the art from the description below.

In at least one embodiment of the present invention, a stack of a plurality of unit cells each having a membrane structure in which an electrolyte membrane and an electrode are formed on a silicon substrate by a free standing method, an oxygen supply line for supplying oxygen to an oxygen electrode of the unit cell, and a fuel supply line for supplying a fuel in a gaseous or liquid state to an anode of the unit cell,
and a ceramic binder for sealing the inside of the stack so that oxygen supplied through the oxygen supply line and fuel supplied through the fuel supply line do not come into contact with each other within the stack.

In at least one embodiment of the present invention, each unit cell constituting the stack of the plurality of unit cells includes a silicon substrate, an electrolyte membrane formed on a first surface of the silicon substrate, a first electrode formed on at least a portion of the first surface of the electrolyte membrane, a recess formed on a second surface of the silicon substrate opposite the first surface such that a portion of the second surface of the electrolyte membrane opposite the first surface that faces the first electrode is exposed, and a second electrode formed on at least the exposed second surface of the electrolyte membrane. The multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode includes a plurality of trench-shaped subcells having a predetermined depth, and the silicon substrate includes a porous portion formed at least near the edge of the recess.

In at least one embodiment of the present invention, each unit cell constituting the stack of the plurality of unit cells includes a silicon substrate, an electrolyte membrane formed on a first surface of the silicon substrate, a first electrode formed on at least a portion of the first surface of the electrolyte membrane, a recess formed so that a portion of the second surface of the electrolyte membrane opposite the first surface is exposed from a second surface of the silicon substrate opposite the first surface, and a second electrode formed on at least the exposed second surface of the electrolyte membrane, and a multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode includes a plurality of trench-shaped subcells having a predetermined depth, and the silicon substrate includes a porous silicon substrate.

At least one embodiment of the present invention provides a solid oxide fuel cell having a stack structure of the above-described thin-film solid oxide fuel cell unit cells.

At least one embodiment of the present invention provides a solid oxide fuel cell package comprising a stack structure of thin-film solid oxide fuel cell unit cells and a housing for accommodating the stack structure of thin-film solid oxide fuel cell unit cells.

In at least one embodiment of the present invention, the fuel cell further comprises a thermal insulation structure disposed between the stack structure of thin-film solid oxide fuel cell unit cells and the housing, the thermal insulation structure including an embossing formed on the inner surface of the housing.

In at least one embodiment of the present invention, the embossing has at least one of the following shapes: a dome-shaped tip, a cone-shaped tip, a pyramid-shaped tip, a multi-projection-shaped tip, and a tapered tip.

In at least one embodiment of the present invention, the thermal insulation structure further includes a first thermal insulation layer and a second thermal insulation layer disposed between the embossing and the stack structure of the thin-film solid oxide fuel cell unit cells.

In at least one embodiment of the present invention, the first thermal insulation layer comprises aluminum;
The second thermal insulating layer includes sapphire.

In at least one embodiment of the present invention, each unit cell constituting the stack of the plurality of unit cells includes a silicon substrate, an electrolyte membrane formed on a first surface of the silicon substrate, a first electrode formed on at least a portion of the first surface of the electrolyte membrane, a recess formed on a second surface of the silicon substrate opposite the first surface such that a portion of the second surface of the electrolyte membrane opposite the first surface that faces the first electrode is exposed, and a second electrode formed on at least the exposed second surface of the electrolyte membrane. The multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode includes a plurality of trench-shaped subcells having a predetermined depth, and the silicon substrate includes a porous portion formed at least near the edge of the recess.

In at least one embodiment of the present invention, each unit cell constituting the unit cell stack includes a silicon substrate, an electrolyte membrane formed on a first surface of the silicon substrate, a first electrode formed on at least a portion of the first surface of the electrolyte membrane, a recess formed so that a portion of the second surface of the electrolyte membrane opposite the first surface is exposed from a second surface of the silicon substrate opposite the first surface, and a second electrode formed on at least the exposed second surface of the electrolyte membrane, and a multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode includes a plurality of trench-shaped subcells having a predetermined depth, and the silicon substrate includes a porous silicon substrate.

At least one embodiment of the present invention provides a solid oxide fuel cell comprising the thin-film solid oxide fuel cell package.

Although the embodiments in this specification are described independently of one another, they may be combined with one another, and combined embodiments are also included within the scope of the present invention.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, embodiments, and features described above, additional aspects, embodiments, and features will become apparent by reference to the drawings and detailed description.

At least one embodiment of the present invention has the advantage of being able to provide a thin-film solid oxide fuel cell package having a stack structure.

Furthermore, at least one embodiment of the present invention has the effect of providing a solid oxide fuel cell including a thin-film solid oxide fuel cell package having a stack structure.

The effects of the present invention are not limited to those mentioned above, and other effects not mentioned will be clearly understood by those with ordinary skill in the art from the description below.

FIG. 1 is a conceptual diagram of a stack structure in accordance with at least one embodiment of the present invention. 1 is a perspective view of a fuel cell package having a stack structure in accordance with at least one embodiment of the present invention. 1 is a cross-sectional side view of a fuel cell package having a stack structure in accordance with at least one embodiment of the present invention. 1 is a conceptual diagram of a fuel cell package insulation structure having a stack structure according to at least one embodiment of the present invention. FIG. 1 is a cross-sectional side view of a unit cell in accordance with at least one embodiment of the present invention. 1A-1C are schematic diagrams illustrating a manufacturing process for a unit cell in accordance with at least one embodiment of the present invention.

The following provides a detailed description of at least one embodiment of a thin-film solid oxide fuel cell having a stress relaxation structure using porous silicon and a method for manufacturing the same, with reference to the accompanying drawings.

Figure 1 is a conceptual diagram of a stack structure 100 of thin-film solid oxide fuel cell unit cells according to at least one embodiment of the present invention. Figure 2 is a perspective view of a fuel cell package having a stack structure 100 according to at least one embodiment of the present invention.

As shown in Figures 1 and 2, a stack structure 100 according to at least one embodiment of the present invention comprises a stack of a plurality of unit cells 110, each having a membrane structure in which an electrolyte membrane and electrodes are formed on a silicon substrate using a free standing method; an oxygen supply line 120 for supplying oxygen to the oxygen electrode of each unit cell 110; a fuel supply line 130 for supplying fuel in a gaseous or liquid state to the fuel electrode of each unit cell 110; and a ceramic binder 140 for sealing the inside of the stack to prevent the oxygen supplied via the oxygen supply line 120 and the fuel supplied via the fuel supply line 130 from coming into contact with each other within the stack.

In the examples shown in Figures 1 and 2, lines for supplying fuel and oxygen (air) are shown in a zigzag pattern along each layer, but this is for ease of explanation; the lines for supplying fuel and oxygen may also be formed as multiple lines parallel to each layer.

The thin-film solid oxide fuel cell manufactured using the MEMS process has a rear-etched membrane structure in which the electrolyte membrane and electrodes are formed on the silicon substrate using a free-standing method.

The electrolyte obtained with such a microstructure reduces its thickness and resistance, thereby offsetting the decrease in ionic conductivity at low temperatures, and the nanostructure of the electrode increases the specific surface area, thereby offsetting the low activity at low temperatures by increasing the density of reaction sites.

In order for a unit cell stack structure to function as a fuel cell when housed in a designated package, the inside of the stack must be sealed to prevent the fuel from coming into contact with oxygen. In the case of polymer fuel cells, the fuel flow path can be sealed using bolts and gaskets, but in the case of small, lightweight thin-film solid oxide fuel cells, the limitations of the membrane structure make it impossible to apply physical force such as bolts and gaskets to seal the inside of the stack.

Therefore, in at least one embodiment of the present invention, as shown in Figures 1 and 2, the layers of the laminate are bonded and sealed using a ceramic binder 140 without the use of fasteners such as bolts or sealing members such as gaskets.

The ceramic binder has excellent heat resistance, water resistance, and adhesive properties, and for example, a typical one-component ceramic binder can be used.

Figure 3 is a side cross-sectional view of a fuel cell package having a stack structure 100 according to at least one embodiment of the present invention. Figure 4 is a conceptual diagram of the thermal insulation structure of a fuel cell package having a stack structure 100 according to at least one embodiment of the present invention.

As shown in Figures 3 and 4, a fuel cell package having a thermal insulation structure according to at least one embodiment of the present invention comprises a housing 200, a unit cell stack 100 housed within the housing 200, and a thermal insulation structure disposed between the housing 200 and the unit cell stack 100.

This MEMS (Micro-electro-mechanical System)-based thin-film solid oxide fuel cell has a unit cell stack 100 made up of a stack of multiple unit cells. Its optimum operating temperature is approximately 500°C, and a separate thin-film heater (not shown) is provided for this purpose.

For such solid oxide fuel cells to operate stably, an insulating structure is required to maintain the internal temperature at an appropriate operating temperature, reduce heat conduction to the outside, and stabilize the surface temperature of the package.

In at least one embodiment of the present invention, the thermal insulation structure disposed between the housing 200 and the unit cell stack 100 includes an embossing 201 formed on the inner surface of the housing 200.

The embossings 201 formed on the inner surface of the housing 200 can minimize heat transmission from the unit cell stack 100 to the outside through the housing 200 by insulating the space between the protrusions and minimizing the cross-sectional contact area with the unit cell stack 100.

In Figure 3, the tip of the embossing 201 is shown as a circular dome shape as an example, but in at least one embodiment of the present invention, the tip of the embossing 201 can be formed in at least one of a dome shape, a cone shape, a pyramid shape, a multi-projection shape, and a tapered shape.

In at least one embodiment of the present invention, the thermal insulation structure disposed between the housing 200 and the unit cell stack 100 may further include a first thermal insulation layer 202 and a second thermal insulation layer 203 disposed between the embossing 201 and the unit cell stack 100.

For more reliable and efficient insulation, in at least one embodiment of the present invention, the first insulating layer 202 can include aluminum and the second insulating layer 203 can include sapphire.

Each unit cell that makes up the unit cell stack 100 has structures such as an electrolyte, a fuel electrode, and a separation membrane, and air passages and fuel passages are formed between each unit cell to allow air and fuel to pass through. However, since various known technologies can be applied to such structures, detailed description thereof will be omitted in this specification.

Figure 5 is a cross-sectional side view of a unit cell 500 according to at least one embodiment of the present invention.

In at least one embodiment of the present invention, the unit cell 500 has a nanomembrane structure in which an electrolyte membrane and electrodes are formed on a silicon substrate using a free-standing method, and may include multiple sub-cells (not shown) formed in a trench shape.

As shown in FIG. 1, a unit cell 500 according to at least one embodiment of the present invention includes a porous portion 560 formed in the silicon substrate 510 at least near the edge of the recessed portion 540.

Figure 5 shows an example in which a porous portion 560 is formed near the edge of the recess portion 540, but the entire silicon substrate 510 may be made porous.

A thin-film solid oxide fuel cell according to at least one embodiment of the present invention may include a stack of unit cells 500.

As shown in FIG. 5, a unit cell 500 according to at least one embodiment of the present invention comprises a silicon substrate 510, an electrolyte membrane 520 formed on a first surface (top surface in the example shown in FIG. 5) of the silicon substrate 510, a first electrode 530 formed on at least a portion of the first surface of the electrolyte membrane 520, a recess 540 formed so that a portion of the second surface (the opposite surface of the electrolyte membrane 520 to the first surface, i.e., the bottom surface) of the silicon substrate 510 is exposed, facing the first electrode 530, and a second electrode 550 formed on the second surface of the electrolyte membrane 520 exposed at least through the recess 540.

The unit cell 500 according to at least one embodiment of the present invention is a MEMS-based thin-film SOFC, and has a structure in which the membrane and electrodes are formed from thin films to minimize ohmic losses due to ionic conduction in the electrolyte and improve operating performance at low temperatures.

To address the drawback of stress occurring near the edge of the membrane (near the edge of the recessed portion 540 in the membrane) during operation, which can damage cells located in this vicinity, the unit cell 500 according to at least one embodiment of the present invention includes a porous portion 560 formed of porosity near at least the edge of the recessed portion 540 in the silicon substrate 510.

In this way, by forming a porous portion 560 formed with porosity at least near the edge of the recessed portion 540 in the silicon substrate 510, it is possible to disperse stress that concentrates near the edge of the membrane (near the edge of the recessed portion 540 on the membrane).

Figure 5 shows an example in which a porous portion 560 is formed near the edge of the recessed portion 540 in the silicon substrate 510 to disperse stress concentrated near the edge of the membrane (near the edge of the recessed portion 540 in the membrane), but it is also possible to make the entire silicon substrate 510 porous to disperse stress concentrated near the edge of the membrane (near the edge of the recessed portion 540 in the membrane).

To this end, in at least one embodiment of the present invention, the unit cell 500 comprises a porous silicon substrate 510, an electrolyte membrane 520 formed on a first surface of the porous silicon substrate 510, a first electrode 530 formed on at least a portion of the first surface of the electrolyte membrane 520, a recess 540 formed on the second surface of the porous silicon substrate 510 so that a portion of the second surface of the electrolyte membrane 520 facing the first electrode 530 is exposed from the second surface of the porous silicon substrate 510, and a second electrode 550 formed on the second surface of the electrolyte membrane 520 exposed at least through the recess 540.

In at least one embodiment of the present invention, the electrolyte membrane 520 may be formed of an ion-conductive ceramic electrolyte membrane using a MEMS process, and the first electrode 530 and the second electrode 550 may be formed using a porous platinum material.

In at least one embodiment of the present invention, electrolyte membrane 520 may be formed from a solid oxygen ion conductor such as yttria stabilized zirconia (YSZ) or a proton conductor such as yttrium doped BaZrO ₃ (BYZ).

Figures 6A through 6G are schematic diagrams illustrating the manufacturing process for a unit cell 500 according to at least one embodiment of the present invention.

As shown in Figure 6A, dielectric films 511 and 512 are deposited on a first surface (top surface in the example shown in Figure 6A) of a silicon substrate 510 whose both surfaces have been polished, and on a second surface (bottom surface in the example shown in Figure 6A), which is the opposite surface of the first surface. Here, SiN can be used for the dielectric films 511 and 512.

Then, as shown in FIG. 6B, the dielectric film 512 deposited on the second surface is removed according to a predetermined pattern. That is, the SiN dielectric film 512 deposited on the second surface is patterned via photolithography using a mask having a predetermined pattern, and then the dielectric film 512 is removed along the pattern via etching using an appropriate etchant.

Then, as shown in FIG. 6C, an electrolyte film 520 is formed on the first surface of the dielectric film 511 deposited on the first surface. The order of the process of removing the dielectric film 512 deposited on the second surface using a predetermined pattern and the process of forming the electrolyte film 520 on the first surface of the dielectric film 511 deposited on the first surface may be reversed.

Then, as shown in FIG. 6D, the portion of the second surface from which the dielectric film 512 has been removed is etched to form a recess 540 so that the dielectric film 511 deposited on the first surface is exposed. At this time, wet etching using a KOH solution can be performed to etch the silicon substrate 510 from below.

Then, as shown in FIG. 6E, the dielectric film 511 deposited on the first surface exposed through the recess 540 and the dielectric film 512 remaining on the second surface are removed.

Then, as shown in FIG. 6F, at least the area around the edge of the recessed portion 540 of the silicon substrate 510 is made porous. For example, a method of forming porous silicon can be used, in which single-crystal silicon is immersed in a hydrofluoric acid solution of a predetermined concentration and then anodized.

Then, as shown in FIG. 6G, a first electrode 530 is formed on at least a portion of the first surface of the electrolyte membrane 520, and the dielectric film 511 deposited on the first surface exposed through the recess portion 540 is removed to form a second electrode 550 on the exposed second surface of the electrolyte membrane 520.

The unit cell 500 manufactured in this way is a MEMS-based thin-film SOFC, and by forming the membrane and electrodes from thin films, it is possible to minimize ohmic losses due to ionic conduction in the electrolyte and improve operating performance at low temperatures.

To prevent stress from concentrating near the edge of the membrane (near the edge of the recessed portion 540 in the membrane) during operation and damaging the cells located in this vicinity, a porous portion 560 is formed in the silicon substrate 510 at least near the edge of the recessed portion 540, thereby dispersing the stress that would otherwise be concentrated near the edge of the membrane (near the edge of the recessed portion 540 in the membrane).

In at least one embodiment of the present invention, the electrolyte membrane 520 may be formed as an ion-conductive ceramic electrolyte membrane using a MEMS process, and the first electrode 530 and the second electrode 550 may be formed using a porous platinum material.

In at least one embodiment of the present invention, electrolyte membrane 520 may be formed from a solid oxygen ion conductor such as yttria stabilized zirconia (YSZ) or a proton conductor such as yttrium doped BaZrO ₃ (BYZ).

Figures 6A to 6G show an example in which a porous portion 560 is formed near the edge of the recessed portion 540 in the silicon substrate 510 to disperse stress concentrated near the edge of the membrane (near the edge of the recessed portion 540 in the membrane), but it is also possible to make the entire silicon substrate 510 porous to disperse stress concentrated near the edge of the membrane (near the edge of the recessed portion 540 in the membrane).

For example, dielectric films 511 and 512 are deposited on the first and second surfaces of a single-crystal silicon substrate 510 whose both surfaces have been polished. Here, SiN can be used for the dielectric films 511 and 512.

Then, the dielectric film 512 deposited on the second surface is removed according to a predetermined pattern. That is, the SiN dielectric film 512 is patterned via photolithography using a mask having a predetermined pattern on the dielectric film deposited on the second surface, and then the dielectric film 512 is removed along the pattern via etching using an appropriate etchant.

Then, an electrolyte film 520 is formed on the first surface of the dielectric film 511 deposited on the first surface. The order of the process of removing the dielectric film 512 deposited on the second surface using a predetermined pattern and the process of forming the electrolyte film 520 on the first surface of the dielectric film 511 deposited on the first surface may be reversed.

Then, the portion of the second surface from which the dielectric film 512 has been removed is etched to form a recess 540 so that the dielectric film 511 deposited on the first surface is exposed. At this time, wet etching using a KOH solution can be performed to etch the silicon substrate 510 from below.

Then, the dielectric film 511 deposited on the first surface exposed through the recess 540 and the dielectric film 512 remaining on the second surface are removed.

Then, the silicon substrate 510 is made porous. For example, a method can be used to form porous silicon by immersing single-crystal silicon in a hydrofluoric acid solution of a predetermined concentration and then anodizing it.

Then, a first electrode 530 is formed on at least a portion of the first surface of the electrolyte membrane 520, and the dielectric film 511 deposited on the first surface exposed through the recess 540 is removed to form a second electrode 550 on the exposed second surface of the electrolyte membrane 520.

The thin-film solid oxide fuel cell 100 manufactured in this way is a MEMS-based thin-film SOFC, and by forming the membrane and electrodes from thin films, it is possible to minimize ohmic losses due to ionic conduction in the electrolyte and improve operating performance at low temperatures.

To prevent stress from concentrating near the edge of the membrane (near the edge of the recessed portion 540 in the membrane) during operation and damaging the cells located in this vicinity, the silicon substrate 510 is made porous, which allows the stress that concentrates near the edge of the membrane (near the edge of the recessed portion 540 in the membrane) to be dispersed.

In at least one embodiment of the present invention, the electrolyte membrane 520 may be formed as an ion-conductive ceramic electrolyte membrane using a MEMS process, and the first electrode 530 and the second electrode 550 may be formed using a porous platinum material.

In at least one embodiment of the present invention, electrolyte membrane 520 may be formed from a solid oxygen ion conductor such as yttria stabilized zirconia (YSZ) or a proton conductor such as yttrium doped BaZrO ₃ (BYZ).

As described above, at least one embodiment of the present invention can provide a thin-film solid oxide fuel cell package having a stack structure.

Furthermore, according to at least one embodiment of the present invention, a solid oxide fuel cell can be provided that includes a thin-film solid oxide fuel cell package having a stack structure.

The present invention has been described above using embodiments, but the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. It is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention.

100: Unit cell stack 110: Unit cell 120: Oxygen supply line 130: Fuel supply line 140: Ceramic binder 200: Housing 201: Embossing 202: First insulating layer 203: Second insulating layer 500: Unit cell 510: Silicon substrate 511, 512: Dielectric film 520: Electrolyte membrane 530: First electrode 540: Recessed portion 550: Second electrode 560: Porous portion

Claims (6)

a stack of a plurality of unit cells, each having a membrane structure in which an electrolyte membrane and electrodes are formed on a silicon substrate;
an oxygen supply line for supplying oxygen to the oxygen electrode of the unit cell;
a fuel supply line for supplying a fuel in a gaseous or liquid state to the anode of the unit cell;
a ceramic binder for sealing the inside of the stack so that the oxygen supplied through the oxygen supply line and the fuel supplied through the fuel supply line do not come into contact with each other within the stack;
Equipped with
Each unit cell constituting the stack of the plurality of unit cells is a unit cell in which a dielectric film is deposited on a first surface and a second surface opposite to the first surface of a silicon substrate, the dielectric film deposited on the second surface being removed according to a predetermined pattern, an electrolyte film is formed on the first surface of the dielectric film deposited on the first surface, the portion of the second surface from which the dielectric film is removed is etched to form a recess so as to expose the dielectric film deposited on the first surface, the dielectric film deposited on the first surface exposed through the recess and the dielectric film remaining on the second surface are removed , at least a side surface of the recess of the silicon substrate is made porous, a first electrode is formed on at least a portion of the first surface of the electrolyte film, and a second electrode is formed on a second surface opposite to the first surface of the electrolyte film exposed by removing the dielectric film deposited on the first surface exposed through the recess.
Stack structure of thin-film solid oxide fuel cell unit cells. a stack of a plurality of unit cells each having a membrane structure in which an electrolyte membrane and electrodes are formed on a silicon substrate;
an oxygen supply line for supplying oxygen to the oxygen electrode of the unit cell;
a fuel supply line for supplying a fuel in a gaseous or liquid state to the anode of the unit cell;
a ceramic binder for sealing the inside of the stack so that the oxygen supplied through the oxygen supply line and the fuel supplied through the fuel supply line do not come into contact with each other within the stack;
Equipped with
Each unit cell constituting the stack of the plurality of unit cells is a unit cell in which a dielectric film is deposited on a first surface and a second surface opposite to the first surface of a single crystal silicon substrate, the dielectric film deposited on the second surface being removed according to a predetermined pattern, an electrolyte film is formed on the first surface of the dielectric film deposited on the first surface, the portion of the second surface from which the dielectric film is removed is etched to form a recess so that the dielectric film deposited on the first surface is exposed, the dielectric film deposited on the first surface exposed through the recess and the dielectric film remaining on the second surface are removed , the silicon substrate is formed to be porous, a first electrode is formed on at least a portion of the first surface of the electrolyte film, and a second electrode is formed on a second surface opposite to the first surface of the electrolyte film exposed by removing the dielectric film deposited on the first surface exposed through the recess.
Stack structure of thin-film solid oxide fuel cell unit cells. A stack structure of thin film solid oxide fuel cell unit cells according to claim 1 or 2,
Solid oxide fuel cell. A stack structure of thin film solid oxide fuel cell unit cells according to claim 1 or 2;
a housing for accommodating the stack structure of the thin film solid oxide fuel cell unit cells;
Equipped with
Solid oxide fuel cell package. Each unit cell constituting the stack of the plurality of unit cells includes a silicon substrate, an electrolyte membrane formed on a first surface of the silicon substrate, a first electrode formed on at least a portion of the first surface of the electrolyte membrane, a recess formed such that a portion of the second surface of the electrolyte membrane, the second surface opposite to the first surface, facing the first electrode, is exposed from a second surface of the silicon substrate opposite to the first surface, and a second electrode formed at least on the exposed second surface of the electrolyte membrane,
the multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode includes a plurality of trench-shaped subcells having a predetermined depth;
5. The solid oxide fuel cell package of claim 4. A thin film solid oxide fuel cell package according to claim 4,
Solid oxide fuel cell.