KR20150066104A - Manufacturing method of nano porous membrane aao for sofc using anodic aluminum oxide - Google Patents

Abstract

The present invention relates to a method to manufacture a nanoporous membrane support body for a fuel cell using an anodic oxidation method. The present invention comprises the steps of: primary anodic oxidizing a surface of a substrate; removing a film which is the primary anodic oxidized; secondary anodic oxidizing the surface of the substrate where the oxidized film is removed; and forming a conductive thin film on the surface of the substrate which is secondary anodic oxidized. According to the present invention, a separator having excellent quality of a membrane separator and excellent electrical conductivity can be manufactured. Therefore, generation of a pinhole of an electrolyte membrane which is one of the factors of reducing a performance of a fuel cell is restrained to improve durability and performance during operation of the fuel cell, and to develop a technology for commercialization. An anode support layer having conductivity can be deposited through various deposition methods to enable the nanoporous membrane support body capable of performing a function of a current collector of the fuel cell.

Description

TECHNICAL FIELD [0001] The present invention relates to a method for manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method,

The present invention relates to a method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method, and more particularly, to a method of manufacturing a nanoporous membrane support for a fuel cell by supporting an electrolyte layer in order to maximize the effect of lowering the operating temperature of a solid oxide fuel cell (SOFC) The present invention relates to a nanoporous membrane support for a fuel cell, which improves the surface quality of the nanoporous membrane support (AAO) and imparts electrical conductivity to the surface thereof.

Generally, a fuel cell is an apparatus for producing electricity electrochemically using hydrogen gas and oxygen gas. The fuel cell is a device for generating electricity (hydrogen) and air (oxygen) continuously supplied from the outside, .

Such a fuel cell generates an electric power by using an oxidation reaction at an anode and a reduction reaction at a cathode. At this time, a membrane-electrode assembly (MEA) composed of a catalyst layer containing platinum or platinum-ruthenium metal and a polymer electrolyte membrane is used to promote the oxidation and reduction reaction, and a membrane electrode assembly And the separation plate is fastened to form a cell structure.

The above-described cell structure is stacked to constitute a fuel cell stack. The fuel cell described above is currently being studied and used for various purposes as an alternative energy source. Typically, the fuel cell is a polymer electrolyte membrane fuel cell (Polymer Electrolyte Membrane Fuel Cell (PEMFC). Polymer electrolyte membrane fuel cells have various advantages such as high output density and energy conversion efficiency, miniaturization and sealing. Therefore, it is used as alternative energy in various fields such as pollution-free automobile, household power generation system, mobile communication equipment, military equipment, and medical equipment.

On the other hand, in order to manufacture a stack generally used in a fuel cell vehicle, a plurality of cells must be stacked, and the stacked cell voltages should be always measured so as to prevent degradation of stack performance during operation do.

That is, the evaluation of the fuel cell stack is made by measuring the current and voltage generated in the fuel cell stack. In particular, the voltage measurement of each cell is an important data indicating the performance and characteristics of each cell in the stack operation .

Meanwhile, a nanoporous membrane support, which is a substrate for supporting an electrolyte layer, is required to realize a thin electrolyte layer necessary for lowering the operating temperature in the process of manufacturing a fuel cell.

Techniques relating to such electrolyte supports have been proposed in Published Patent Applications No. 2011-0126786 and No. 1277893.

Hereinafter, the fuel cells disclosed in the prior art patents No. 2011-0126786 and No. 1277893 will be described briefly.

Fig. 1 shows a process drawing of a bonding step in the case of using the filler according to the prior art 1. 1, the solid oxide fuel cell according to the prior art 1 includes an electrolyte 41, a single cell 45 including a fuel electrode 40 and an air electrode 42, which are formed on both sides of the electrolyte 41, A bonding material 30 formed on one side surface of the unit cell so as to be bonded to the metal foam support 20, a metal foaming support 20 bonded to the bonding material 30, And an air passage 13 for supplying air to the air electrode 42 which is formed in contact with one surface of the air electrode 42. The air passage 42 is provided with a supply passage 12 for supplying a fuel gas to the fuel electrode 40, And a separation plate 11 formed thereon.

FIG. 2 shows a manufacturing process of a metal-supported solid oxide fuel cell according to the prior art 2. As shown in FIG. Referring to FIG. 2, a method of manufacturing a metal-supported metal oxide fuel cell according to Prior Art 2 includes the steps of: preparing a metal support 101, a first electrode 103, an electrolyte 107 and a second electrode 109; Forming a laminate by laminating the metal support 101, the first electrode 103, the electrolyte 107 and the second electrode 109; Sintering the laminate; And forming a manifold (402) on the sintered laminate.

However, when the metal foam support 20 and the metal support 101 are used in the fuel cell according to the prior arts 1 and 2, defects are generated due to the rough electrode surface along the pinhole, and these defects are short ) And leakage, which leads to deterioration of cell performance, improvement of the film quality of the surface of the nanoporous membrane support, and application of electrical conductivity properties to the surface of the nanoporous membrane support.

KR 2011-0126786 A KR 1277893 B1

SUMMARY OF THE INVENTION An object of the present invention is to solve the problems of the prior art as described above, and it is an object of the present invention to improve the film quality of the surface of the nanoporous membrane support formed by performing the anodic oxidation process secondarily, The present invention provides a method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method, which provides an excellent surface film and conductivity to a nanoporous membrane support, which is an insulator, by providing excellent electrical conductivity properties through a conductive material formed on the surface of the membrane will be.

According to an aspect of the present invention, there is provided a method of manufacturing a semiconductor device, the method including: a first anodizing the surface of a substrate; Removing the primary anodized film; Secondary anodizing the surface of the substrate from which the oxide film has been removed; And forming an electroconductive thin film on the surface of the substrate subjected to the secondary anodization. The present invention also provides a method for manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method.

Also, the electrolyte used in the secondary anodizing step in the present invention may be an acidic solution, and the acidic solution may be applied to sulfuric acid (H2SO4), oxalic acid (H2C2O4), or phosphoric acid (H3PO4).

The substrate in the present invention may be selected from among aluminum (Al), titanium (TI), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb) and tungsten (W).

In addition, in the conductive thin film forming step of the present invention, an electrically conductive material such as carbon, nickel, gold, silver, copper, or platinum may be used as the thin film.

The conductive thin film forming step of the present invention may be performed by any one of doping, screen printing, dip coating, sol-gel method, and spray coating . ≪ / RTI >

In the conductive thin film forming step of the present invention, an acetylene (C2H2) gas is used as a dopant source at the time of doping and may be performed at a temperature ranging from 400 to 600 ° C.

In addition, the thickness of the support of the present invention may be in the range of 1 to 100 mu m.

According to the present invention, it is possible to manufacture a separation membrane having excellent membrane quality and excellent electrical conductivity, thereby suppressing the occurrence of pinholes in the electrolyte membrane, which is one of the causes of decrease in fuel cell performance, and improving durability and performance in fuel cell operation and commercialization And the oxide support layer having conductivity can be deposited through various deposition techniques. Therefore, the present invention can also be used as a fuel cell current collector.

BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a process diagram of an adhering step in the case of using the filler of the prior art 1. Fig.
2 is a manufacturing process diagram of a metal-supported solid oxide fuel cell according to the prior art 2. FIG.
3 is a block diagram illustrating a method of fabricating a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention.
4 is a process diagram of a method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method according to the present invention.
FIG. 5 is a graph illustrating a first and a second anodization process in a method of preparing a nanoporous membrane support for a fuel cell using an anodic oxidation method according to the present invention.
6 is an actual image of a support manufactured by the method of manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention.
7 is an image showing the roughness of the surface of the support produced by the method of manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention.
8 is an image obtained by doping a conductive material on the surface of a support prepared by the method of manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention.

The terms or words used in the present specification and claims are intended to mean that the inventive concept of the present invention is in accordance with the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the term in order to explain its invention in the best way Should be interpreted as a concept.

Throughout the specification, when an element is referred to as "comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, a method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method according to the present invention will be described in detail with reference to the drawings.

FIG. 3 is a block diagram showing a method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method according to the present invention, and FIG. 4 is a process diagram showing a method for manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method according to the present invention FIG. 5 is a graph illustrating the first and second anodization processes in the method of preparing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention. 7 shows an actual image of a support manufactured by the method for manufacturing a nanoporous membrane support for a battery, and FIG. 7 shows the roughness of the surface of the support produced by the method for manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention. And FIG. 8 shows an example Doping (doping) of conductive material on the surface of the support produced by the anodic oxidation method for producing a fuel cell using the nanoporous membrane support is shown by the image.

According to these drawings, the method of manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method of the present invention comprises a first anodizing step (S100), a first anodizing film removing step (S110), a second anodizing step (S120) A thin film forming step (S130), and a thin film thickness of the support is formed within a range of 1 to 100 mu m.

The first anodizing step S100 is a step in which the anodic oxide film 210 is formed by first anodizing the surface of the substrate 200, which is the base material of the support. (See Fig. 4 (b)).

At this time, the step of preparing the substrate before the primary anodizing step (S100) is performed first. (See Fig. 4 (a)).

During the first anodization step S100, the substrate 200 may be formed of aluminum (Al), titanium (Ti), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium Tungsten (W) or the like.

The primary anodic oxide removing step S110 is a step of removing the anodic oxide film 210 formed on the substrate 200 by the primary anodizing step S100, Etching process for removing the reaction layer, etching process for the pore layer, and the like. (See Fig. 4 (c)).

The secondary anodizing step S120 is a step of secondary anodizing the surface of the substrate 200 from which the anodic oxide film 210 is removed after the primary anodizing film removing step S110. (See Fig. 4 (d)).

At this time, the electrolyte used in the secondary anodizing step (S120) may be an acidic solution such as sulfuric acid (H2SO4), oxalic acid (H2C2O4), phosphoric acid (H3PO4)

The conductive thin film forming step S130 is a step of forming the conductive thin film 204 on the surface of the substrate 200 subjected to the secondary anodization using a conductive material. (See Fig. 4 (e)).

At this time, the conductive thin film 204 may be formed of an electrically conductive material such as carbon, nickel, gold, silver, copper, platinum or the like and may be formed of one or more kinds of alloys It is possible.

In addition, the conductive thin film formation step (S130) is performed to impart an electrical conductivity function to the nanoporous membrane support having an insulator property through an electroconductive thin film (204). At this time, the conductive thin film forming step (S130) may be performed by a method such as doping, screen printing, dip coating, sol-gel method, spray coating, Electro-plating, electrophoresis, and the like.

For example, when the conductive thin film formation step (S130) is performed by doping, acetylene (C2H2) gas or the like is used as a dopant source, and a conductive thin film may be formed at a temperature ranging from 400 to 600 ° C have.

At this time, the conductive thin film 204 formed on the substrate 200 by using acetylene (C2H2) gas as a dopant source is formed by a doping process. The doping process is a process in which a nanostructure, which is an insulator, It can be converted into a structure. Carbon doping of the conductive material is performed by heating argon (Argon), acetylene (C2H2) gas and the like in the mixed atmosphere at 550 DEG C for 30 minutes to 90 minutes (preferably 1 hour) Respectively.

Furthermore, the anodic oxidation process is one of the surface treatment techniques for metal, which has been widely used for preventing corrosion or for coloring metal surfaces by forming an oxide film on the metal surface. However, the anodic oxidation process has been widely used for nanostructures such as nano-dots, nanowires, nanotubes, Or a membrane for forming a nano structure is controlled according to need, so that a membrane or a secondary battery for seawater desalination or a battery (battery) of a fuel cell, which serves as a membrane in the environment and industrial fields, Fuel cell separators, and the like.

Al, Ti, Zr, Hf, Ta, Nb, W and the like are known as metals capable of forming a nano support by anodic oxidation. Among them, aluminum anodic oxide films are easy to manufacture, Unlike metals, electrolyte handling is relatively safe, and nanopore and thickness control is easy.

In order to achieve the pore alignability of the nanoporous membrane structure and the superiority of such a membrane quality, it is not possible to produce an excellent separation membrane only by a cleaning process for cleaning the substrate (Al metal) surface, a polishing process for surface planarization, and an anodic oxidation process. Additional processes such as a secondary anodization process for the preparation of an excellent nanoporous membrane support, an anodization process for removing the unreacted layer, an etching process for the pore layer, etc., which are left after the anodic oxidation, are preferable for the production of an excellent membrane structure .

Therefore, according to the method of manufacturing a nanoporous membrane support for a fuel cell using the anodic oxidation method according to the present invention, different applied voltages and electrolytes can be used depending on the resources of the nanoporous membrane support to be manufactured. In order to improve the film quality of the membrane surface, Adjust the electrolyte concentration and temperature.

In the present invention, a nanoporous membrane support is manufactured through a secondary anodization process. A relatively thin anodization layer 210 is formed on the substrate 200 by a primary anodization process (S100) The oxide film 210 is removed (etched or the like) by the primary anodic oxide removing step S110 to leave a seed of a concave shape 202 on the substrate 200, followed by a secondary anodizing step The desired surface roughness is reduced on the seeds 202 through the steps of S120, thereby making it possible to manufacture a nanoporous membrane having excellent membrane quality.

Here, FIG. 5 is a graph showing numerical values in the experimental process such as voltage, current density and temperature applied in the primary anodizing step (S100) and the secondary anodizing step (S120).

Next, a membrane having a good film quality is manufactured through the secondary anodizing step (S120), and then the conductive thin film forming step (S130) is performed to impart excellent electrical conductivity properties.

FIG. 6 is an actual image of a nanoporous membrane support manufactured according to an example of the present invention, and FIG. 7 is a result of analyzing the roughness of the surface of the manufactured nanoporous membrane support through an AFM analyzer.

FIG. 8 shows a nanoporous membrane support (AAO) specimen (see FIG. 8 (a)) before heat treatment and a specimen doped by heat treatment at a high temperature for 1 hour (see FIG. 8 (b)). In particular, as shown in FIG. 8 (b), the surface of the doped sample turned black when the carbon was doped on the surface of the specimen, and the surface was carbonized to change the color to black.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. This is possible.

Therefore, the scope of the present invention should not be limited by the described embodiments, but should be determined by the equivalents of the appended claims, as well as the appended claims.

200: substrate
202: Seed
204: Conductive thin film
210: oxide film

Claims (7)

A first anodizing the surface of the substrate;
Removing the primary anodized film;
Secondary anodizing the surface of the substrate from which the oxide film has been removed; And
And forming an electroconductive thin film on the surface of the substrate subjected to the secondary anodization. The method for manufacturing a nanoporous membrane support for a fuel cell according to claim 1,
The method according to claim 1,
The method of manufacturing a nanoporous membrane support for a fuel cell using an anodic oxidation method, wherein an acidic solution is used for the electrolyte used in the secondary anodizing step and the acidic solution is applied to sulfuric acid (H2SO4), oxalic acid (H2C2O4), phosphoric acid (H3PO4) .
The method according to claim 1,
Wherein the substrate is a nanoporous membrane for a fuel cell using anodic oxidation selected from aluminum (Al), titanium (TI), zirconium (Zr), hafnium (Hf), tantalum (Ta), niobium (Nb), and tungsten Lt; / RTI >
The method according to claim 1,
Wherein the thin film is formed of an electrically conductive material such as carbon, nickel, gold, silver, copper or platinum in the conductive thin film forming step.
The method according to claim 1,
The conductive thin film forming step may be anodization, which is performed by any one of doping, screen printing, dip coating, sol-gel method and spray coating. A method for manufacturing a nanoporous membrane support for a fuel cell using the method.
6. The method of claim 5,
Wherein the conductive thin film forming step uses an acetylene (C2H2) gas as a dopant source at a doping time and is performed at a temperature in a range of 400 to 600 ° C. The method for manufacturing a nanoporous membrane support for a fuel cell according to claim 1,
The method according to claim 1,
Wherein the support has a thickness in the range of 1 to 100 mu m. ≪ RTI ID = 0.0 > 11. < / RTI >

Images