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KR-102961235-B1 - Thinfilm Solid Oxide Fuel Cell Package Having Stack Structure

KR102961235B1KR 102961235 B1KR102961235 B1KR 102961235B1KR-102961235-B1

Abstract

The stack structure of a thin-film solid oxide fuel cell unit cell comprises a stack of multiple unit cells, each having a membrane structure in which an electrolyte membrane and an electrode are formed in a free-standing manner 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 fuel in a gaseous or liquid state to the fuel electrode of the unit cell; and a ceramic binder for sealing the interior 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.

Inventors

  • 김영현
  • 이준영

Assignees

  • 주식회사 에이엠엑스랩

Dates

Publication Date
20260508
Application Date
20220331

Claims (12)

  1. A stack of multiple unit cells, each comprising a membrane structure in which an electrolyte film and an electrode are formed in a free-standing manner on a silicon substrate; An oxygen supply line for supplying oxygen to the oxygen electrode of the above unit cell; A fuel supply line for supplying fuel in a gaseous or liquid state to the fuel electrode of the unit cell; and A ceramic binder for sealing the interior of a laminate 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 laminate. Equipped with, Each unit cell constituting a stack of the plurality of unit cells comprises a silicon substrate, an electrolyte film 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 film, a recess portion formed such that a portion facing the first electrode on the second surface of the electrolyte film, which is opposite to the first surface of the silicon substrate, is exposed from a second surface of the silicon substrate, which is opposite to the first surface, and a second electrode formed on at least the exposed second surface of the electrolyte film. The multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode comprises a plurality of sub-cells in the form of trenches formed to a predetermined depth, and The silicon substrate comprises a porous portion formed porously at least near the edge of the recess portion. Stack structure of a thin-film solid oxide fuel cell unit cell.
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  3. In paragraph 1, Each unit cell constituting a stack of the plurality of unit cells comprises a silicon substrate, an electrolyte film 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 film, a recess portion formed such that a portion facing the first electrode on the second surface of the electrolyte film, which is opposite to the first surface of the silicon substrate, is exposed from a second surface of the silicon substrate, which is opposite to the first surface, and a second electrode formed on at least the exposed second surface of the electrolyte film. The multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode comprises a plurality of sub-cells in the form of trenches formed to a predetermined depth, and The above silicon substrate includes a porous silicon substrate, Stack structure of a thin-film solid oxide fuel cell unit cell.
  4. A stack structure of a thin-film solid oxide fuel cell unit cell as described in any one of claims 1 to 3, Solid oxide fuel cell.
  5. Stack structure of a thin-film solid oxide fuel cell unit cell as described in claim 1; and Housing for accommodating the stack structure of the above-described thin-film solid oxide fuel cell unit cell , equipped with Solid oxide fuel cell package.
  6. In paragraph 5, An insulating structure disposed between the stack structure of the above-described thin-film solid oxide fuel cell unit cell and the housing. Further equipped with, The above insulation structure includes an embossing formed on the inner surface of the housing, Solid oxide fuel cell package.
  7. In paragraph 6, The above embossing has a tip formed of at least one of a dome shape, a cone shape, a pyramid shape, a multi-protrusion shape, and a tapered shape, Solid oxide fuel cell package.
  8. In paragraph 6, The above insulation structure further comprises a first insulation layer and a second insulation layer disposed between the embossing and the stack structure of the thin-film solid oxide fuel cell unit cell, Solid oxide fuel cell package.
  9. In paragraph 8, The above first insulation layer comprises aluminum, and The above second insulating layer includes sapphire, Solid oxide fuel cell package.
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  11. In paragraph 5, Each unit cell constituting the unit cell stack comprises a silicon substrate, an electrolyte film 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 film, a recess formed such that a portion facing the first electrode on the second surface of the electrolyte film is exposed from a second surface of the silicon substrate that is opposite to the first surface of the silicon substrate, and a second electrode formed on at least the exposed second surface of the electrolyte film. The multilayer structure formed by the first electrode, the electrolyte membrane, and the second electrode comprises a plurality of sub-cells in the form of trenches formed to a predetermined depth, and The above silicon substrate includes a porous silicon substrate, Solid oxide fuel cell package.
  12. A thin-film solid oxide fuel cell package having the package described in any one of claims 5 through 11, Solid oxide fuel cell.

Description

Thinfilm Solid Oxide Fuel Cell Package Having Stack Structure 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 high-efficiency energy conversion device that converts chemical energy into electrical energy, and it is a fuel cell that uses a solid oxide membrane as an electrolyte. YSZ (Yttria Stabilized Zirconia) is mainly used as the electrolyte for the electrolyte membrane of SOFCs, and thin-film SOFCs fabricated through a Micro-electro-mechanical System (MEMS) process consist of a back-etched membrane structure in which an electrolyte membrane and electrodes are formed on a silicon substrate in a free-standing manner (see, for example, Patent Document 1). Here, for an effective microstructure, the electrolyte can offset the decrease in ionic conductivity at low temperatures by reducing resistance through a decrease in thickness, and the electrode can offset the low activity at low temperatures by increasing the specific surface area through nanostructuring, thereby increasing the reaction site density. In order for a unit cell to operate as a fuel cell while housed within a specified package, it is necessary to seal the inside of the stack so that the fuel is separated from oxygen (air). In the case of polymer fuel cells, the fuel flow paths can be sealed using bolts and gaskets, but in the case of small, lightweight thin-film solid oxide fuel cells, there is a problem in that sealing inside the stack is not easy due to the limitations of the membrane structure in which the electrolyte membrane and electrodes are formed in a free-standing manner on a silicon substrate. FIG. 1 is a conceptual diagram of a stack structure according to at least one embodiment of the present invention. FIG. 2 is a perspective view of a fuel cell package having a stack structure according to at least one embodiment of the present invention. FIG. 3 is a side cross-sectional view of a fuel cell package having a stack structure according to at least one embodiment of the present invention. FIG. 4 is a conceptual diagram of an insulation structure of a fuel cell package having a stack structure according to at least one embodiment of the present invention. FIG. 5 is a side cross-sectional view of a unit cell according to at least one embodiment of the present invention. FIGS. 6A to 6G are conceptual diagrams for explaining the manufacturing process of a unit cell according to at least one embodiment of the present invention. Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings. FIG. 1 is a conceptual diagram of a stack structure (100) of a thin-film solid oxide fuel cell unit cell according to at least one embodiment of the present invention. FIG. 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 illustrated in FIGS. 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 film and an electrode are formed in a free-standing manner on a silicon substrate, 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 so that the oxygen supplied through the oxygen supply line (120) and the fuel supplied through the fuel supply line (130) do not come into contact with each other within the stack. In the example illustrated in FIGS. 1 and 2, lines are shown in which fuel and oxygen are supplied in a zigzag pattern along each layer, but this is for convenience of explanation, and the lines for supplying fuel and oxygen may be formed as multiple lines parallel to each layer. Thin-film solid oxide fuel cells fabricated through MEMS processes consist of a back-etched membrane structure that forms an electrolyte membrane and electrodes on a silicon substrate in a free-standing manner. The electrolyte obtained with such a microstructure offsets the decrease in ionic conductivity at low temperatures by reducing resistance through reduced thickness, and the nanostructuring of the electrode offsets the low activity at low temperatures by increasing the specific surface area through an increase in reaction site density. In order for a fuel cell to operate while being housed in a package consisting of stacks of unit cells, the inside of the stack must be sealed so that the fuel does not come into contact with oxygen. In the case of polymer fuel cells, the fuel flow paths can be sealed using bolts and gaskets, but in the case of small, lightweight thin-film solid oxide fuel cells, physical force such as bolts and gaskets cannot be applied