US-12620604-B2 - Fuel cell and method for producing same

US12620604B2US 12620604 B2US12620604 B2US 12620604B2US-12620604-B2

Abstract

A fuel cell 1 includes a silicon substrate 2 , a porous support material layer 5 , a plurality of holes 60 or columns 40 , and a stacked body. The stacked body includes an upper electrode layer 10 , a solid electrolyte layer 100 and a lower electrode layer 20 . The upper electrode layer 10 is also formed on a surface parallel to a main surface of the silicon substrate 2 in a manner of being continuous to the upper electrode layer formed in the plurality of holes 60 or columns 40 , or the lower electrode layer 20 is also formed on a surface parallel to the main surface of the silicon substrate 2 in a manner of being continuous to the lower electrode layer 20 formed in the plurality of holes 60 or columns 40 . The stacked body is supported by the porous support material layer 5 in at least upper end portions and lower end portions of the plurality of holes 60 or columns 40.

Inventors

Yoshitaka Sasago
Noriyuki Sakuma
Natsuki Yokoyama
Atsushi UNEMOTO
Takashi Tsutsumi
Aritoshi Sugimoto
Toru Aramaki
Nobuyuki Mise

Assignees

HITACHI HIGH-TECH CORPORATION

Dates

Publication Date: 20260505
Application Date: 20200513

Claims (14)

1 . A fuel cell comprising: a first substrate; a first support material layer formed on one surface or both surfaces of the first substrate; a plurality of holes or columns formed in the first support material layer in a manner of extending in a direction perpendicular to a main surface of the first substrate; and a stacked body formed by a film forming process on a surface of the plurality of holes or columns that is not parallel to the main surface, the stacked body including an upper electrode layer, a solid electrolyte layer, and a lower electrode layer, wherein the upper electrode layer is also formed on a surface parallel to the main surface on the first support material layer in a manner of being continuous to the upper electrode layer formed in the plurality of holes or columns, and the lower electrode layer is also formed on a surface parallel to the main surface on the first support material layer in a manner of being continuous to the lower electrode layer formed in the plurality of holes or columns, the stacked body is supported by the first support material layer between upper end portions of the plurality of holes and between lower end portions of the plurality of holes, or between upper end portions of the plurality of columns and lower end portions of the plurality of columns, the plurality of holes or columns include a plurality of first through holes penetrating the first support material layer and the first substrate, side walls of the plurality of first through holes include the stacked body, and hollows are formed on outer peripheral sides of the side walls of the plurality of first through holes.
2 . The fuel cell according to claim 1 , wherein the plurality of holes or columns include a plurality of bottomed holes formed in the first support material layer, the first support material layer is a porous support material layer, and the stacked body is formed on side walls and bottom portions of the plurality of bottomed holes.
3 . The fuel cell according to claim 2 , wherein the first support material layer includes a metal layer, and the lower electrode layer is electrically connected to one side surface of the first substrate via the metal layer and the first substrate.
4 . The fuel cell according to claim 2 , wherein in the first support material layer, a surface opposite to a surface on which the plurality of bottomed holes are formed is supported by a second support material layer.
5 . The fuel cell according to claim 1 , wherein the plurality of holes or columns include a plurality of columns formed in the first support material layer.
6 . The fuel cell according to claim 2 , wherein a thickness of a part of the first support material layer in which the plurality of bottomed holes are formed is constant.
7 . The fuel cell according to claim 1 , further comprising: a second substrate supporting the first substrate, wherein a plurality of second through holes are formed in the second substrate, the first substrate and the second substrate are bonded to each other, and a part of the second through holes is connected to any one of the first through holes, and a remaining part of the second through holes is connected to the hollows.
8 . The fuel cell according to claim 1 , wherein the first substrate includes a thick region and a thin region having a thickness less than that of the thick region, and the plurality of first through holes are formed in the thin region.
9 . The fuel cell according to claim 1 , wherein the side walls of the plurality of first through holes include a porous support material layer supporting the stacked body on an outer peripheral side of the side walls.
10 . The fuel cell according to claim 1 , wherein in the plurality of first through holes, an opening area in a cross section parallel to the main surface decreases from one end portion of the first through hole toward the other end portion of the first through hole.
11 . A method for manufacturing a fuel cell, the method comprising: a step of forming a metal-oxide layer on a surface of a substrate; a step of forming an uneven structure in the metal-oxide layer; a step of forming a lower electrode layer, a solid electrolyte layer, and an upper electrode layer in this order on a surface of the uneven structure; a step of removing a part of the substrate that is in contact with the metal-oxide layer; and a step of making the metal-oxide layer porous by reduction annealing.
12 . The method for manufacturing a fuel cell according to claim 11 , wherein the uneven structure includes a plurality of bottomed holes or columns formed on a surface of the metal-oxide layer.
13 . A method for manufacturing a fuel cell, the method comprising: a step of forming a first support material layer on both surfaces of a first substrate; a step of forming a plurality of first through holes penetrating the first substrate and the first support material layer; a step of forming a stacked body on an inner peripheral surface of the plurality of first through holes and at least one side surface of the first support material layer, the stacked body including a lower electrode layer, a solid electrolyte layer, and an upper electrode layer; and a step of forming a hollow by removing a part of the first substrate that is in contact with the stacked body formed in the plurality of first through holes.
14 . The method for manufacturing a fuel cell according to claim 13 , further comprising: a step of forming a plurality of second through holes in a second substrate; and a step of bonding the first substrate and the second substrate and connecting at least a part of the plurality of first through holes and at least a part of the plurality of second through holes, wherein the step of forming the hollow includes a step of removing a part of the first substrate exposed through the second through hole.

Description

TECHNICAL FIELD The present invention relates to a fuel cell and a method for manufacturing the same, and relates to, for example, a fuel cell in which a solid electrolyte layer is formed by a film forming process and a method for manufacturing the same. BACKGROUND ART Non-PTL 1 discloses a cell technique for forming an anode layer, a solid electrolyte layer, and a cathode layer of a fuel cell film by a thin film forming process in a fuel cell. In order to improve an output power per area of a solid oxide fuel cell, it is necessary to reduce an internal resistance. As the internal resistance, an ohmic resistance of the solid electrolyte layer can be reduced by reducing a thickness of the solid electrolyte layer, but a polarization resistance of the cathode layer and the anode layer cannot be reduced. Therefore, there is a limit to the improvement of the output power by reducing the internal resistance, and it is necessary to increase the output power by other measures. Non-PTL 2 discloses a technique in which an anode layer, a solid electrolyte layer, and a cathode layer of a fuel cell film having a three-dimensional structure are formed on a substrate by a thin film forming process to increase a surface area, thereby improving an output power per projected area on the substrate. PTL 1 discloses a stack including a continuous solid phase matrix and tubular fuel cells embedded in the matrix. PTL 2 discloses a configuration in which a porous substrate having a plurality of through holes is a fuel cell block including a cylindrical fuel cell element formed by sandwiching a solid electrolyte layer between an air electrode layer and a fuel electrode layer in the through holes. CITATION LIST Patent Literature PTL 1: JP-T-2005-518075PTL 2: JP-A-2005-174846 Non Patent Literature Non-PTL 1: Journal of Power Sources 194 (2009) pp. 119-129Non-PTL 2: Nano Letter 13 (2013) pp. 4551-4555 SUMMARY OF INVENTION Technical Problem In the related art, there is a problem that it is difficult to increase the output power per projected area on the substrate and form the fuel cell film in a wide region of the substrate. As described in Non-PTL 2, when the fuel cell film having the three-dimensional structure is prepared on the substrate by the thin film forming process, mechanical strength of the thin film becomes weak. Therefore, it is difficult to form the fuel cell film having the three-dimensional structure in the wide region. In the methods in PTLs 1 and 2, when a projection plane perpendicular to the hole is considered, the surface area of the fuel cell per projected area increases. In addition, since the fuel cell is supported by the porous substrate, strength can be secured. However, since the fuel cells formed in the individual holes are formed separately, the number of steps for manufacturing the fuel cell is proportional to the number of holes. Therefore, a cost per output power is relatively high. The invention has been made in view of the above problems, and an object of the invention is to provide a fuel cell capable of increasing the output power per projected area on the substrate and forming the fuel cell film in the wide region of the substrate, and a method for manufacturing the same. Solution to Problem An example of a fuel cell according to the invention includes: a first substrate; a first support material layer formed on one surface or both surfaces of the first substrate; a plurality of holes or columns formed in the first support material layer in a manner of extending in a direction perpendicular to a main surface of the first substrate; and a stacked body formed by a film forming process on a surface of the plurality of holes or columns that is not parallel to the main surface, the stacked body including an upper electrode layer, a solid electrolyte layer, and a lower electrode layer. The upper electrode layer is also formed on a surface parallel to the main surface in a manner of being continuous to the upper electrode layer formed in the plurality of holes or columns, or the lower electrode layer is also formed on a surface parallel to the main surface in a manner of being continuous to the lower electrode layer formed in the plurality of holes or columns, and the stacked body is supported by the first support material layer in at least upper end portions and lower end portions of the plurality of holes or columns. An example of a method for manufacturing a fuel cell according to the invention includes: a step of forming a metal-oxide layer on a surface of a substrate; a step of forming an uneven structure in the metal-oxide layer; a step of forming a lower electrode layer, a solid electrolyte layer, and an upper electrode layer in this order on a surface of the uneven structure; a step of removing a part of the substrate that is in contact with the metal-oxide layer; and a step of making the metal-oxide layer porous by reduction annealing. An example of a method for manufacturing a fuel cell according