JP2010044934A - Fuel cell, and manufacturing method for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell in which an electrolyte membrane is thinly formed, and to provide a manufacturing method thereof. <P>SOLUTION: The fuel cell has the electrolyte membrane for passing ions, a fuel electrode formed on one surface of the electrolyte membrane, and an air electrode formed on the other surface of the electrolyte membrane. The fuel electrode includes porous nickel as a principal component, and does not include an oxide included in the electrolyte membrane. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell and a method for manufacturing the fuel cell.

  Fuel cells are widely researched and developed as a next-generation mainstream power supply system that extracts power by an electrochemical reaction between an oxidizing agent and a reducing agent. In a solid oxide fuel cell which is a kind of fuel cell device, a power generation cell in which a fuel electrode is formed on one surface of a solid oxide electrolyte and an air electrode is formed on the other surface is used.

As a method for producing a solid oxide fuel cell, a fuel electrode paste is conventionally screened on an electrolyte in which an oxygen ion conductive ceramic material such as a zirconia oxide such as yttria stabilized zirconia (YSZ) is used. A method is known in which a fuel electrode is formed by applying a belt shape by a printing method, followed by drying and sintering at a predetermined time and temperature (see Patent Document 1).
JP 2005-276535 A

By the way, when a solid oxide fuel cell is manufactured by the above-mentioned method, since the electrolyte is used as a substrate, a certain degree of strength is required. Therefore, the thickness is preferably, for example, 200 to 1000 μm. It has been known. A method is also known in which a porous fuel electrode is formed in advance and then a dense electrolyte membrane is formed on the upper surface thereof. However, even when a solid oxide fuel cell is manufactured by any method, it is actually difficult to form a thin electrolyte membrane to a thickness of, for example, several microns to about a submicron.
An object of the present invention is to provide a fuel cell having a thin electrolyte membrane and a method for manufacturing the fuel cell.

A fuel cell according to claim 1 is provided.
An electrolyte membrane through which ions pass, a fuel electrode formed on one surface of the electrolyte membrane, and an air electrode formed on the other surface of the electrolyte membrane,
The fuel electrode includes porous Ni as a main component and does not include an oxide included in the electrolyte membrane.

The invention according to claim 2 is the fuel cell according to claim 1,
The fuel electrode is characterized in that an Al ₂ O ₃ thin film is present on the surface.

The invention according to claim 3 is the fuel cell according to claim 1 or 2, wherein
The electrolyte membrane is YSZ.

The invention according to claim 4 is the fuel cell according to any one of claims 1 to 3,
The air electrode is LSM or LSC.

A method of manufacturing a fuel cell according to the invention of claim 5 comprises:
Forming an electrolyte membrane containing an electrolyte that allows ions to pass through at least part of a plate-like substrate containing Ni as a main component;
Next, forming an air electrode on at least a part of the electrolyte membrane;
Next, the method includes a step of electrolytically etching at least a part of a region of the substrate that is not covered with the electrolyte membrane using an electrolytic solution containing alcohol and lithium chloride.

A sixth aspect of the present invention is the method of manufacturing a fuel cell according to the fifth aspect,
The step of forming the electrolyte membrane includes:
Including a step of forming a YSZ film on a portion of the surface of the substrate where the electrolyte film and the air electrode are formed,
The step of forming the air electrode includes:
The method includes a step of forming an LSM film or an LSC film on a surface of the YSZ film opposite to the base.

The invention according to claim 7 is the method of manufacturing a fuel cell according to claim 5 or 6,
After the step of forming the air electrode, and before the step of electrolytic etching, including a step of forming a NiCr film on at least a part of a region of the substrate that is not covered with the electrolyte film,
The electrolytic etching step is characterized in that at least a part of a portion of the base on which the NiCr film is formed is etched.

Invention of Claim 8 is a manufacturing method of the fuel cell of Claim 5 or 6,
After the step of forming the electrolyte membrane and the air electrode, and before the step of electrolytic etching, an Al ₂ O ₃ film is formed on at least a part of a region of the substrate that is not covered with the electrolyte membrane. Including the step of forming,
The electrolytic etching step is characterized in that at least a part of the portion of the substrate on which the Al ₂ O ₃ film is formed is etched.

The invention according to claim 9 is the method of manufacturing a fuel cell according to any one of claims 5 to 8,
The electrolytic etching step includes a step of forming a mask so as to cover at least the air electrode.

Invention of Claim 10 is a manufacturing method of the fuel cell as described in any one of Claims 5-8,
The step of performing the electrolytic etching includes a step of immersing at least a part of the portion of the substrate excluding the region where the electrolyte membrane and the air electrode are formed in the electrolytic solution.

  According to the present invention, it is possible to provide a solid oxide fuel cell having a thin electrolyte membrane and a method for manufacturing the same.

  The best mode for carrying out the present invention will be described below with reference to the drawings. However, although various technically preferable limitations for implementing the present invention are given to the embodiments described below, the scope of the invention is not limited to the following embodiments and illustrated examples.

〔Electronics〕
FIG. 1 is a block diagram showing a portable electronic device 100 equipped with a fuel cell device 1. The electronic device 100 is a portable electronic device such as a notebook personal computer, a PDA, an electronic notebook, a digital camera, a mobile phone, a wristwatch, a register, and a projector.

The electronic device 100 includes an electronic device main body 901, a DC / DC converter 902, a secondary battery 903, and the like, and the fuel cell device 1.
The electronic device main body 901 is driven by electric power supplied from the DC / DC converter 902 or the secondary battery 903. The DC / DC converter 902 converts the electric power generated by the fuel cell device 1 into an appropriate voltage and then supplies it to the electronic device main body 901. In addition, the DC / DC converter 902 charges the secondary battery 903 with the power generated by the fuel cell device 1, and when the fuel cell device 1 is not operating, the power stored in the secondary battery 903 is used as the electronic device main body. 901 is supplied.

[Fuel cell device]
The fuel cell device 1 includes a fuel container 2, a pump 3, a reaction device 10, and the like. The fuel container 2 of the fuel cell device 1 is detachably provided, for example, with respect to the electronic device 100, and the pump 3 and the reaction device 10 are incorporated in the main body of the electronic device 100, for example.

The fuel container 2 stores a liquid mixture of liquid fuel (for example, hydrocarbon fuel such as methanol) and water. Liquid fuel and water may be stored in separate containers.
The pump 3 sucks the liquid mixture in the fuel container 2 and sends it to the vaporizer 4 in the reaction apparatus 10.

A vaporizer 4, a reformer 6, a power generation cell 8 and a catalytic combustor 9 are accommodated in the reaction apparatus 10. In order to prevent heat conduction and convection due to gas molecules, the internal space of the reaction apparatus 10 is maintained at a pressure lower than the atmospheric pressure, for example, 10 Pa or less, more preferably 1 Pa or less.
The vaporizer 4, the reformer 6, and the catalytic combustor 9 are provided with electric heaters and temperature sensors 4a, 6a, and 9a, respectively. Since the electric resistance values and temperatures of the electric heater / temperature sensors 4a, 6a, 9a have a one-to-one correspondence in the measurement temperature range, the electric heater / temperature sensors 4a, 6a, 9a are connected to the vaporizer 4, the reformer 6, It also functions as a temperature sensor that measures the temperature of the catalytic combustor 9.

  The liquid mixture sent from the pump 3 to the vaporizer 4 is heated to about 110 to 160 ° C. by the heat of the electric heater / temperature sensor 4a or the heat propagated from the catalyst combustor 9, and is vaporized to generate a mixture. . The air-fuel mixture (reactant) generated in the vaporizer 4 is sent to the reformer 6.

  The reformer 6 is a reactor according to the present invention. FIG. 2 is an exploded perspective view showing a schematic configuration of the reformer 6. As shown in FIG. 2, a main body (reactor main body) 61 of the reformer 6 is formed by a box body 62 opened on one surface, a bottom plate 63 closing the opening of the box body 62, and the box body 62 and the bottom plate 63. And a plurality of partition plates (catalysts) 65 to 71 that are accommodated in the internal space and partition the internal space. The box 62 and the bottom plate 63 are made of a metal material such as stainless steel. In addition, although the detail about the formation material of the partition plates 65-71 is mentioned later, the main material is Ni steel.

  An inlet port 72 is formed in the vicinity of one corner 73 of the four corners of the bottom plate 63, and an outlet port 74 is formed in the corner 75 adjacent thereto. The inlet port 72 and the outlet port 74 are holes that penetrate the bottom plate 63.

  The partition plates 65 to 71 are bent in an L shape, whereby flanges 65 a to 71 a (flanges 70 a and 71 a are not shown) are formed on one side of the partition plates 65 to 71. By joining the flanges 65 a to 71 a to one surface of the bottom plate 63, the partition plates 65 a to 71 a are provided on one surface of the bottom plate 63 while standing at a right angle to the bottom plate 63.

  The partition plates 65 to 71 are arranged so as to be parallel to two opposite sides 633 and 634 of the four sides 631 to 634 of the bottom plate 63. The partition plates 65 to 68 are provided near one side 631 that is not parallel to them, the partition plates 69 to 71 are provided near the opposite side 632 of the side 631, and the partition plates 65 to 68 and the partition plates 69 to 71 are provided. They are staggered.

  In the completed reactor 6, the partition plates 65 to 71 enter the box body 62, the bottom plate 63 blocks the opening of the box body 62, and the bottom plate 63 is joined to the box body 62. Of the sides perpendicular to the bottom plate 63 in the partition plates 65 to 68, one side closer to the side 631 of the bottom plate 63 is arranged along the side 631 of the bottom plate 63 among the four side walls of the box 62. The side that is in contact with the side wall 621 and is closer to the side 632 of the bottom plate 63 is separated from the opposing side wall 622 that is disposed along the side 632 of the bottom plate 63. Of the sides perpendicular to the bottom plate 63 in the partition plates 69 to 71, the side closer to the side 632 of the bottom plate 63 contacts the side wall 622, and the side closer to the side 631 of the bottom plate 63 is separated from the side wall 621. . Of the partition plates 65 to 68, the side that contacts the side wall 621 and the side wall 621 may be joined. The same applies to the side wall 632 and the side that contacts the side wall 632 among the partition plates 69 to 71.

  The internal space surrounded by the box body 62 and the bottom plate 63 is partitioned by the partition plates 65 to 71, whereby a flow path 95 is formed in the internal space. Since the partition plates 65 to 68 and the partition plates 69 to 71 are alternately arranged, the internal flow path 95 is a meandering flow path.

  Porous portions 90 are formed on two main surfaces of the partition plates 65 to 71 parallel to the sides 633 and 634 of the bottom plate 63. The porous portion 90 is represented by uniform grids in the drawing, but actually has irregular irregularities. In the porous portion 90, the Ni base as a catalyst is exposed. As a result, the air-fuel mixture (reactant) passing through the flow path 95 comes into contact with Ni to cause a catalytic reaction. A gas mixture (reformed gas) such as hydrogen as a fuel, carbon dioxide, and a small amount of carbon monoxide as a by-product is generated by a reforming reaction between the fuel and water mixture. When the fuel is methanol, the reformer 6 mainly performs a steam reforming reaction as shown in the following formula (1).

CH ₃ OH + H ₂ O → 3H ₂ + CO ₂ (1)

  Carbon monoxide is by-produced in a trace amount by an equation such as the following equation (2) that occurs sequentially following the chemical reaction equation (1).

H ₂ + CO ₂ → H ₂ O + CO (2)

The reformed gas generated by the chemical reaction formulas (1) and (2) is sent to the power generation cell 8.
FIG. 3 is a schematic diagram of the power generation cell 8. As shown in FIG. 3, the power generation cell 8 includes a solid oxide electrolyte 81 that is an electrolyte membrane according to the present invention, and a fuel electrode 82 (anode) and an air electrode 83 formed on both surfaces of the solid oxide electrolyte 81. (Cathode), an anode collector electrode 84 joined to the fuel electrode 82 and having a flow path 86 formed on its joint surface, and a cathode collector electrode 85 joined to the air electrode 83 and formed with a flow path 87 on its joint surface Is provided. The power generation cell 8 is accommodated in the housing 91.

The solid oxide electrolyte 81 is made of zirconia-based (Zr _1-x Y _x ) O _{2-x / 2} (YSZ) or the like, and the air electrode 83 is made of La _1-x Sr _x MnO ₃ (LSM) or La. _1-x Sr _x CoO ₃ (LSC) or the like, Ni or the like for the fuel electrode 82, LaCr (Mg) O ₃ , (La, Sr) CrO ₃ , NiAl + Al ₃ for the anode collector electrode 84 and the cathode collector electrode 85. O ₃ or the like can be used respectively. As will be described later, Ni + YSZ or the like has conventionally been used for the fuel electrode for structural reasons.

  The power generation cell 8 is heated to about 500 to 1000 ° C. by the heat of the electric heater / temperature sensor 9a and the catalytic combustor 9, and the reaction described later takes place.

  Air is sent to the air electrode 83 via the flow path 87 of the cathode collector electrode 85. In the air electrode 83, oxygen ions are generated by oxygen and electrons supplied from the cathode output electrode 21b as shown in the following equation (3).

O ₂ + 4e ⁻ → 2O ₂ ⁻ (3)

The solid oxide electrolyte 81 has oxygen ion permeability, and allows the oxygen ions generated by the chemical reaction formula (3) to pass through the air electrode 83 to reach the fuel electrode 82.
The reformed gas discharged from the reformer 6 is sent to the fuel electrode 82 through the flow path 86 of the anode collector electrode 84. In the fuel electrode 82, a reaction represented by the following equations (4) and (5) occurs between oxygen ions that have permeated the solid oxide electrolyte 81 and the reformed gas.

H ₂ + O ₂ ⁻ → H ₂ O + 2e ⁻ (4)
CO + O ₂ ⁻ → CO ₂ + 2e ⁻ (5)

  Electrons emitted by the chemical reaction formulas (4) and (5) are supplied to the air electrode 83 from the cathode output electrode 21b through external circuits such as the fuel electrode 82, the anode output electrode 21a, and the DC / DC converter 902.

  An anode output electrode 21 a and a cathode output electrode 21 b are connected to the anode collector electrode 84 and the cathode collector electrode 85, respectively, and are drawn out through the housing 91. Here, the casing 91 is made of, for example, a Ni-based alloy, and the anode output electrode 21a and the cathode output electrode 21b are insulated from the casing 91 and drawn out by an insulating material such as glass or ceramic. As shown in FIG. 1, the anode output electrode 21a and the cathode output electrode 21b are connected to, for example, a DC / DC converter 902.

  The reformed gas (off gas) that has passed through the flow path of the anode collector electrode 84 contains unreacted hydrogen, water vapor, and carbon dioxide. The off gas is supplied to the catalytic combustor 9.

  Air that has passed through the flow path 87 of the cathode collector electrode 85 is supplied to the catalytic combustor 9 together with the off-gas. Air contains unreacted oxygen. A flow path is formed inside the catalytic combustor 9, and a Pt-based catalyst is supported on the wall surface of the flow path.

  A mixed gas (combustion gas) of off gas and air flows through the flow path of the catalytic combustor 9 and is heated by the electric heater / temperature sensor 9a. Of the combustion gas flowing through the flow path of the catalytic combustor 9, hydrogen is combusted by the catalyst, thereby generating combustion heat. The exhaust gas after combustion containing water vapor and carbon dioxide is discharged from the catalytic combustor 9 to the outside of the reaction apparatus 10.

  The combustion heat generated in the catalytic combustor 9 is used to maintain the temperature of the power generation cell 8 at a high temperature (about 500 to 1000 ° C.). The heat of the power generation cell 8 is conducted to the reformer 6 and the vaporizer 4 and used for evaporation in the vaporizer 4 and a steam reforming reaction in the reformer 6.

[Method for producing catalyst in reformer]
Next, a method for producing a catalyst in the reformer 6 will be described. As for the production method of this catalyst, a method of directly performing electrolytic etching on a Ni substrate (first catalyst production method), a method of performing electrolytic etching after forming a NiCr film on the Ni substrate (second catalyst production method) In addition, there is a method (third catalyst production method) in which electrolytic etching is performed after an Al ₂ O ₃ film is formed on a Ni substrate, which will be described in order below.

[First Catalyst Production Method]
FIG. 4 is a conceptual diagram showing a schematic configuration of an etching apparatus used in the first catalyst manufacturing method. As shown in FIG. 4, the etching apparatus 200 includes a container 201 and a DC power source 202. A Ni base 203a as a member to be etched is connected to the anode side of the DC power source 202, and a noble metal plate 204 made of, for example, a gold-based material is connected to the cathode side. In the container 201, the Ni base body 203a and the noble metal plate 204 are accommodated so as to face each other, and an electrolytic solution 205 is accommodated so that they are immersed.

The electrolytic solution 205 is obtained by dissolving a predetermined amount of lithium chloride using alcohol (for example, ethanol) as a solvent.
The Ni base body 203 a becomes the partition plates 65 to 71, and before being immersed in the electrolytic solution 205, the region other than the portion that becomes the porous portion 90 is masked so as not to contact the electrolytic solution 205. . Note that the Ni substrate 203a may be any substrate that includes Ni as a main component acting as a catalyst. In this case, the oxide contained in the solid oxide electrolyte 81 may not be included.
Then, after the Ni base 203 a and the noble metal plate 204 are disposed to face each other in the electrolytic solution 205, a DC voltage is applied between the Ni base 203 a and the noble metal plate 204 by the DC power source 202. As a result, the surface of the Ni substrate 203a, specifically, the surface of the portion that becomes the porous portion 90 is electrolytically etched to become porous. According to the above-described method, a catalyst that contains Ni as a main component and does not contain an oxide contained in the solid oxide electrolyte 81 can be produced.

[Second Catalyst Production Method]
FIGS. 5A to 5C are schematic cross-sectional views showing state fluctuations of the Ni base 203b when the second catalyst production method is executed. As shown in FIGS. 5A and 5B, in the second catalyst manufacturing method, first, NiCr films 206 are formed on both surfaces of the Ni base 203b before processing by a well-known sputtering method. After sputtering, the distribution of Cr in the NiCr film 206 is not uniform, and a portion with more Cr and a portion with less Cr are formed on the surface of the NiCr film 206.

  The Ni substrate 203b after film formation is set in the etching apparatus 200, and electrolytic etching is performed with the same electrolytic solution 205 as in the first catalyst manufacturing method. At this time, in the NiCr film 206, the portion with more Cr is difficult to be etched, and the portion with less Cr is easily etched. For this reason, as shown in FIG. 5C, etching proceeds in a portion where Cr is less and a large number of holes 207 are formed. Thereby, the Ni substrate 203b becomes porous.

  In the description here, the electrolytic solution 205 has been described by exemplifying an electrolytic solution in which a predetermined amount of lithium chloride is dissolved using ethanol as a solvent in the same manner as in the first catalyst manufacturing method. If is added, it becomes possible to generate a more effective catalytic reaction.

[Third Catalyst Production Method]
FIGS. 6A to 6D are schematic cross-sectional views showing state fluctuations of the Ni base 203c when the third catalyst production method is executed. As shown in FIGS. 6A and 6B, in the third catalyst manufacturing method, first, an Al film 208 is formed on both surfaces of the Ni base 203c before processing by a known sputtering method.

When a well-known anodizing process (for example, Hideki Masuda, Future Materials, 5 (2005), etc.) is applied to the Ni substrate 203c after film formation, the Al film 208 is oxidized as shown in FIG. The Al ₂ O ₃ film 209 is formed. Further, when the Al film 208 is oxidized by anodic oxidation, a large number of fine holes 210 in submicron units are regularly formed.

Thereafter, the Ni substrate 203c on which the porous Al ₂ O ₃ film 209 is formed is set in the etching apparatus 200, and electrolytic etching is performed with the electrolytic solution 205 similar to the first catalyst manufacturing method. At this time, as shown in FIG. 6D, etching proceeds from the micro holes 210 of the Al ₂ O ₃ film 209, and holes 211 are also formed in the Ni base 203c. Thereby, the Ni substrate 203c becomes porous.

[Fuel Cell Manufacturing Method]
Next, a method for manufacturing the power generation cell 8 as a fuel cell according to the present invention will be described. There are two methods for manufacturing the power generation cell 8: a method using NiCr (first battery manufacturing method) and a method using Al (second battery manufacturing method), which will be described in order below.

[First Battery Manufacturing Method]
FIGS. 7A to 7E are schematic cross-sectional views showing state fluctuations of the Ni base 203d when the first battery manufacturing method is executed. Here, the thickness of each film may be other ratios, and is not limited to the illustrated example. As shown in FIGS. 7A and 7B, in the first battery manufacturing method, a YSZ film 221 is formed on one surface 220 of the Ni base 203d that becomes the fuel electrode 82 by a known sputtering method. The YSZ film 221 becomes the solid oxide electrolyte 81 described above.

  Next, as shown in FIG. 7C, an LSM film 223 is formed on the exposed surface 222 of the YSZ film 221, that is, the surface 222 opposite to the Ni base 203d by a known coating method or sputtering method. To do. The LSM film 223 becomes the air electrode 83.

  An example of a coating method that is a method of forming the LSM film 223 will be described. First, a predetermined amount of La nitrate, Sr nitrate, and Mn nitrate is dissolved in a solvent composed of 1-methyl-2-pyrrolidone. This solution is applied to the exposed surface 222 of the YSZ film 221 by spin coating. After application, the LSM film 223 is formed by drying and crystallization. As a characteristic of this method, when the film thickness of the LSM film 223 is about 100 nm, it becomes a clean film with a smooth surface. Moreover, when the film thickness is about 200 nm, bubbles are generated on the surface, but the adhesion is good. By using this characteristic, it is possible to form a porous LSM film 223 having a thickness of about 1 μm.

  It is also possible to form an LSC film other than the LSM film 223 and use the air electrode 83 as the LSC film.

  Thereafter, as shown in FIG. 7D, a NiCr film 225 is formed on the other surface 224 of the Ni base 203d by a known sputtering method. After sputtering, the distribution of Cr in the NiCr film 225 becomes non-uniform, and a portion with more Cr and a portion with less Cr are formed on the surface of the NiCr film 225.

  After forming the NiCr film 225, the Ni substrate 203d is set in the etching apparatus 200, and electrolytic etching is performed with the electrolytic solution 205 similar to the first catalyst manufacturing method. At this time, in the NiCr film 225, the portion with more Cr is difficult to be etched, and the portion with less Cr is easy to be etched. Therefore, as shown in FIG. Many will be formed. As a result, the Ni substrate 203d becomes porous. Further, during the electrolytic etching, the exposed surface of the LSM film 223, that is, the surface 222 opposite to the YSZ film 221 is masked so as not to come into contact with the electrolytic solution 205, and this mask is removed after the electrolytic etching. .

In the description here, the electrolytic solution 205 has been described by exemplifying an electrolytic solution in which a predetermined amount of lithium chloride is dissolved using ethanol as a solvent in the same manner as in the first catalyst manufacturing method. If is added, it becomes possible to generate a more effective catalytic reaction.
Then, the anode collector electrode 84 is joined to the Ni base 203d that becomes the fuel electrode 82, and the cathode collector electrode 85 is joined to the LSM film 223 that becomes the air electrode 83, thereby generating power as shown in FIG. The cell 8 will be manufactured.

[Second Battery Manufacturing Method]
FIGS. 8A to 8F are schematic cross-sectional views showing state fluctuations of the Ni base 203e when the second battery manufacturing method is executed. Here, the thickness of the cornea may be other ratios and is not limited to the illustrated example. As shown in FIGS. 8A and 8B, in the second battery manufacturing method, a YSZ film 231 is formed on one surface 230 of the Ni base 203e to be the fuel electrode 82 by a known sputtering method. This YSZ film 231 becomes the solid oxide electrolyte 81.

  Next, as shown in FIG. 8C, an LSM film 233 is formed on the exposed surface 232 of the YSZ film 231, that is, the surface 232 opposite to the Ni base 203e by a known coating method or sputtering method. To do. The LSM film 233 becomes the air electrode 83. It is also possible to form an LSC film other than the LSM film 233 and use the LSC film as the air electrode 83.

  Thereafter, as shown in FIG. 8D, an Al film 235 is formed on the other surface 234 of the Ni base 203e by a known sputtering method.

When the Ni base 203e is subjected to a known anodizing process after the Al film 235 is formed, the Al film 235 is oxidized to become an Al ₂ O ₃ film 236 as shown in FIG. Further, when the Al film 235 is oxidized by anodic oxidation, a large number of fine holes 237 in submicron units are regularly formed.
Thereafter, the Ni substrate 203e on which the porous Al ₂ O ₃ film 236 is formed is set in the etching apparatus 200, and electrolytic etching is performed with the electrolytic solution 205 similar to the first catalyst manufacturing method. At this time, as shown in FIG. 8F, etching proceeds from the fine hole 237 of the Al ₂ O ₃ film 236, and a hole 238 is also formed in the Ni base 203e. Thereby, the Ni substrate 203e becomes porous. During the electrolytic etching, the exposed surface of the LSM film 223, that is, the surface opposite to the YSZ film 231 is masked so as not to come into contact with the electrolytic solution 205, and this mask is removed after the electrolytic etching.

  Then, the anode collector electrode 84 is joined to the Ni base 203d that becomes the fuel electrode 82, and the cathode collector electrode 85 is joined to the LSM film 223 that becomes the air electrode 83, thereby generating power as shown in FIG. The cell 8 will be manufactured.

  As described above, according to the present embodiment, the Ni bases 203a, 203b, and 203c as the catalyst of the reformer 6 and the Ni bases 203d and 203e as the fuel electrode 82 of the power generation cell contain alcohol and lithium chloride. It is made porous by electrolytic etching using the electrolytic solution contained. Thereby, the surface area of the Ni bases 203a, 203b, 203c, 203d, and 203e can be increased, and the catalytic effect by the Ni bases 203a, 203b, 203c, 203d, and 203e can be sufficiently obtained.

  Here, in the case where the NiCr films 206 and 225 are formed on the surfaces of the Ni bases 203b and 203d before the electrolytic etching, as in the second catalyst manufacturing method and the first battery manufacturing method, the NiCr film 206 is formed. , 225, a large number of holes 207, 226 can be formed in the Ni bases 203b, 203d by utilizing the variation in Cr distribution.

On the other hand, when the porous Al ₂ O ₃ films 209 and 237 are formed on the surfaces of the Ni bases 203c and 203e before the electrolytic etching, as in the third catalyst manufacturing method and the second battery manufacturing method. In this case, a large number of holes 211 and 238 can be formed in the Ni bases 203c and 203e by utilizing the regular fine holes 210 and 237 formed in the Al ₂ O ₃ films 209 and 237 by anodic oxidation.

  By the way, conventionally, when a fuel electrode is manufactured using Ni fine particles and YSZ, Ni and YSZ are mixed in order to prevent Ni micron-order fine particles from sintering and growing together with a temperature rise. I was using what I did. The reason why Ni and YSZ are mixed in this way is due to manufacturing reasons, and as a fuel electrode, YSZ is essentially unnecessary. Conventionally, since the method for making YSZ porous is different from the usual film forming method, it has been difficult to form a thin YSZ layer itself. For these reasons, it has been difficult to reduce the thickness and size of the entire power generation cell 8.

On the other hand, in the first and second battery manufacturing methods described above, since the Ni bases 203d and 203e are made porous by electrolytic etching, YSZ is unnecessary. Therefore, it is not necessary to form the YSZ layer porous. Therefore, as described above, thin and dense YSZ films 221 and 231 can be formed by a general film forming method such as a well-known sputtering method. As a result, the YSZ films 221 and 231 that are electrolyte films can be formed thinner than in the case where the conventional porous YSZ is used as the air electrode, and thus the entire power generation cell 8 can be reduced in size. It becomes possible. By realizing thinning of the YSZ films 221 and 231, the power generation cell 8 can be improved in performance, and the operating temperature of the power generation cell 8 can be lowered.
Note that the present invention is not limited to the above embodiment, and can be modified as appropriate.

It is a block diagram which shows the portable electronic device carrying the fuel cell apparatus which concerns on this embodiment. It is a disassembled perspective view which shows schematic structure of the reformer with which the fuel cell apparatus of FIG. 1 is equipped. It is a schematic diagram of the power generation cell with which the fuel cell apparatus of FIG. 1 is equipped. It is a conceptual diagram which shows schematic structure of the etching apparatus used with the 1st catalyst manufacturing method. It is a schematic cross section which shows the state fluctuation | variation of Ni base | substrate at the time of performing the 2nd catalyst manufacturing method, (a) is the state before a process, (b) is the state after film forming, (c) is after electrolytic etching. Shows the state. It is a schematic cross section which shows the state fluctuation | variation of Ni base | substrate at the time of performing the 3rd catalyst manufacturing method, (a) is the state before a process, (b) is the state after film forming, (c) is after anodization (D) shows the state after electrolytic etching. It is a schematic cross section which shows the state fluctuation | variation of Ni base | substrate at the time of performing a 1st battery manufacturing method, (a) is the state before a process, (b) is the state after YSZ film formation, (c) is an LSM film | membrane. The state after formation, (d) shows the state after forming the NiCr film, and (e) shows the state after electrolytic etching. It is a schematic cross section which shows the state fluctuation | variation of Ni base | substrate at the time of performing a 2nd battery manufacturing method, (a) is a state before a process, (b) is a state after YSZ film formation, (c) is an LSM film | membrane. The state after formation, (d) shows the state after the formation of the Al film, (e) shows the state after the formation of the Al ₂ O ₃ film, and (f) shows the state after the electrolytic etching.

Explanation of symbols

1 Fuel cell device 6 Reformer (reactor)
8 Power generation cell (fuel cell)
61 Body (Reactor body)
65-71 Partition plate (catalyst)
81 Solid oxide electrolyte (electrolyte membrane)
82 Fuel electrode 83 Air electrode 95 Flow path 100 Electronic device 200 Etching apparatus 203a, 203b, 203c, 203d, 203e Base (Ni base)
205 Electrolyte 206,225 NiCr film 209,237 Al ₂ O ₃ film 221,231 YSZ film 223,233 LSM film

Claims (10)

An electrolyte membrane through which ions pass, a fuel electrode formed on one surface of the electrolyte membrane, and an air electrode formed on the other surface of the electrolyte membrane,
The fuel electrode according to claim 1, wherein the fuel electrode contains porous Ni as a main component and does not contain an oxide contained in the electrolyte membrane. The fuel cell according to claim 1, wherein
The fuel electrode is characterized in that a thin film of Al ₂ O ₃ is present on the surface thereof. The fuel cell according to claim 1 or 2,
The fuel cell, wherein the electrolyte membrane is YSZ. In the fuel cell as described in any one of Claims 1-3,
The fuel cell, wherein the air electrode is LSM or LSC. Forming an electrolyte membrane containing an electrolyte that allows ions to pass through at least part of a plate-like substrate containing Ni as a main component;
Next, forming an air electrode on at least a part of the electrolyte membrane;
And a step of electrolytically etching at least a part of a region of the substrate that is not covered with the electrolyte membrane using an electrolytic solution containing alcohol and lithium chloride. . In the manufacturing method of the fuel cell according to claim 5,
The step of forming the electrolyte membrane includes:
Including a step of forming a YSZ film on a portion of the surface of the substrate where the electrolyte film and the air electrode are formed,
The step of forming the air electrode includes:
A method of manufacturing a fuel cell, comprising: forming an LSM film or an LSC film on a surface of the YSZ film opposite to the base. In the manufacturing method of the fuel cell of Claim 5 or 6,
After the step of forming the air electrode, and before the step of electrolytic etching, including a step of forming a NiCr film on at least a part of a region of the substrate that is not covered with the electrolyte film,
The method of manufacturing a fuel cell, wherein the electrolytic etching step etches at least a part of a portion of the base on which the NiCr film is formed. In the manufacturing method of the fuel cell according to claim 5 or 6,
After the step of forming the electrolyte membrane and the air electrode, and before the step of electrolytic etching, an Al ₂ O ₃ film is formed on at least a part of a region of the substrate that is not covered with the electrolyte membrane. Including the step of forming,
The method of manufacturing a fuel cell, wherein the electrolytic etching step etches at least a part of a portion of the substrate on which the Al ₂ O ₃ film is formed. In the manufacturing method of the fuel cell as described in any one of Claims 5-8,
The electrolytic etching step includes a step of forming a mask so as to cover at least the air electrode. In the manufacturing method of the fuel cell as described in any one of Claims 5-8,
The electrolytic etching step includes a step of immersing at least a part of the substrate excluding the region where the electrolyte membrane and the air electrode are formed in the electrolytic solution. .

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