KR20220068205A - Oxygen electrode comprising a dual plating catalyst, water electrolysis device, regenerative fuel cell including the same and method for preparing the oxygen electrode - Google Patents

Abstract

According to the specification, disclosed are an oxygen electrode including a double plating catalyst, a water electrolysis device including the same, a renewable fuel cell, and a method for manufacturing the oxygen electrode. The present invention lowers the loading of platinum and iridium oxide.

Description

Oxygen electrode including double plating catalyst, water electrolysis device including same, regenerative fuel cell, and method for manufacturing the oxygen electrode OXYGEN ELECTRODE}

The present invention relates to an oxygen electrode including a double plating catalyst, a water electrolysis device including the same, a regenerative fuel cell, and a method for manufacturing the oxygen electrode. More specifically, the present invention provides a layer of platinum (Pt) and iridium oxide on a substrate. An oxygen electrode including a double plating catalyst in which layers are sequentially electroplated, a water electrolysis device including the same, a regenerative fuel cell, and a method for manufacturing the oxygen electrode.

Renewable energies such as solar and wind power are in the spotlight as future alternative energy to existing fossil fuels as climate change problems become serious. Since electricity generated from renewable energy is intermittent, it needs to be stored in a form of fuel, and hydrogen is the most promising alternative fuel candidate in this regard. In the case of water electrolysis, which is used as a technology for producing hydrogen fuel, hydrogen and oxygen can be produced by electrolysis of water, and in the case of a fuel cell, electricity can be produced using hydrogen and oxygen fuel. In addition, a lot of research has been conducted on fuel cells to the extent that they are applied to automobiles and commercialization of hydrogen vehicles is achieved.

On the other hand, referring to Chemical Formulas 1 and 2 below, the renewable fuel cell is a system that can perform both the functions of the water electrolysis and the fuel cell, and is a device used for storing and converting electrochemical energy. 1, 2A, and 2B , a unitized regenerative fuel cell (hereinafter, may be referred to as URFC) is a cell that performs two functions in one device, and the capital cost compared to a separate type regenerative fuel cell It has a reducing effect.

[Formula 1] During water electrolysis operation,

Oxygen electrode: H ₂ O → 1/2O ₂ + 2H ⁺ + 2e ^-

Hydrogen electrode: 2H ⁺ + 2e ^- → H ₂

[Formula 2] During fuel cell operation,

Oxygen electrode: 1/2O ₂ + 2H ⁺ + 2e ^- → H ₂ O

Hydrogen electrode: H ₂ → 2H ⁺ + 2e ^-

However, the current integrated regenerative fuel cell requires an excessive amount of precious metal catalyst to manufacture the electrode, so the system cost is very high. For this reason, noble metal catalysts such as Ir (or RuO ₂ , iridium oxide) and Pt have been used.

Although many non-noble metal catalysts have been studied to solve this problem, there is still no substitute for a catalyst having as high activity and stability as Ir (or RuO ₂ , iridium oxide) and Pt under acidic conditions. Accordingly, it is necessary to elevate high activity with a reduced noble metal catalyst content.

Korean Patent Publication No. 10-2010-0088176 Korean Patent Publication No. 10-2017-0058352

T. Ioroi, N. Kitazawa, K. Yasuda, Y. Yamamoto, H. Takenaka. Journal of Applied Electrochemistry 31 (2001): 1179-1183. Wenli Yao, Jun Yang, Jiulin Wang, and Yanna Nuli. Electrochemistry Communications 9 (2007): 1029-1034. Byung-Seok Lee, Hee-Young Park, Min Kyung Cho, JeaWoo Jung, Hyoung-Juhn Kim, Dirk Henkensmeier, Sung Jong Yoo, Jin Young Kim, Sehkyu Park, Kwan-Young Lee, Jong Hyun Jang. Electrochemistry Communications 64 (2016) 14-17. 2016 Int. J. Hydro. energy, 41, 20650-20659 2012 Int. J. Hydro. Energy, 37, 13522-13528 2011 Electrochimica Acta, 56, 4287-4293 2012 J. Power Sources., 198, 23- 29

An object of the present invention is an oxygen electrode, specifically a platinum (Pt) layer and iridium oxide on a substrate, which exhibits excellent effects while lowering the loading amount of noble metals, particularly platinum and iridium oxide. To provide an oxygen electrode including a double plating catalyst in which layers are sequentially electroplated, a water electrolysis device including the same, a regenerative fuel cell, and a method for manufacturing the oxygen electrode.

An exemplary embodiment of the present invention includes a substrate; a platinum (Pt) layer formed on the substrate by electroplating; It provides an oxygen electrode comprising; an iridium oxide layer formed on the platinum (Pt) layer by electroplating.

An exemplary embodiment of the present invention provides a water electrolysis device including the above-described oxygen electrode.

An exemplary embodiment of the present invention provides a renewable fuel cell including the above-described oxygen electrode.

In an exemplary embodiment of the present invention, there is provided a method for manufacturing the above-described oxygen electrode, comprising: forming a platinum (Pt) layer on a substrate by electroplating; and forming an iridium oxide layer on the platinum (Pt) layer by electroplating.

Oxygen electrode according to the present invention is a platinum (Pt) layer and iridium oxide on a substrate Since the layers are sequentially electroplated and supported by an electrochemical reaction rather than a physical bond, an excellent effect can be exhibited when operating a water electrolysis device or a regenerative fuel cell while reducing the loading of precious metals, particularly platinum.

In addition, the oxygen electrode manufacturing method according to the present invention can support a nanometer-level thin catalyst layer during electroplating of a platinum (Pt) layer or an iridium oxide layer, and the catalytically active area lost compared to the spray method is reduced. , it is possible to manufacture an oxygen electrode exhibiting high catalyst activity with a small loading amount.

1 is a conceptual diagram for the operation of a general integrated regenerative fuel cell.
2A and 2B are conceptual diagrams schematically illustrating a water electrolysis operation and a fuel cell operation of a general integrated regenerative fuel cell.
3A is a diagram illustrating a conventional method for preparing a catalyst using a spray method, and FIG. 3B is a diagram illustrating an electroplating method according to an embodiment of the present invention.
4A and 4B are diagrams illustrating a conventional oxygen electrode, and FIG. 4C is a diagram illustrating an oxygen electrode according to an embodiment of the present invention.
5a to 5c show an oxygen electrode 5a electroplated with an iridium oxide layer on a substrate, an oxygen electrode 5b with an electroplated platinum (Pt) layer on the substrate, and a platinum (Pt) layer and oxide on the substrate, respectively. It is a scanning microscope photograph of the surface of the oxygen electrode 5c on which the iridium layer is electroplated one after another.
6A and 6B are graphs showing the performance of the fuel cell and water electrolysis according to the electroplating time of the platinum (Pt) layer of the oxygen electrode in Examples and Comparative Examples of the present invention.
7A and 7B show the performance of water electrolysis of the double plating electrode according to the platinum (Pt) layer loading amount of the oxygen electrode ( FIG. 7A ) and the total noble metal catalyst loading amount in the oxygen electrode in Examples and Comparative Examples of the present invention It is a graph showing the performance (FIG. 7b) of water electrolysis.
8 is a diagram illustrating a case in which only a platinum (Pt) layer is electroplated on a substrate of an oxygen electrode, only an iridium oxide layer is electroplated, and a platinum (Pt) layer and an iridium oxide layer on the substrate in Examples and Comparative Examples of the present invention; It is a graph showing the water electrolysis performance in the case of electroplating sequentially.
9 is an oxygen electrode in which a platinum (Pt) layer and an iridium oxide layer are sequentially electroplated on the substrate of the oxygen electrode when the loading amount of the electroplated iridium oxide is the same in Examples and Comparative Examples of the present invention; A graph showing fuel cell performance when a platinum (Pt) layer is formed on the iridium oxide layer by a spray method after electroplating the iridium oxide layer on the substrate.
10 is a graph showing the circulation efficiency of the integrated renewable fuel cell at a similar catalyst loading amount in Examples and Comparative Examples (reference 1-4) of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The embodiments of the present invention disclosed in the text are illustrated for the purpose of explanation only, and the embodiments of the present invention may be embodied in various forms and should not be construed as being limited to the embodiments described in the text. .

The present invention can make various changes and can have various forms, and the embodiments are not intended to limit the present invention to a specific disclosed form, and all changes, equivalents or substitutes included in the spirit and scope of the present invention should be understood as including

In the present specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

oxygen electrode

Exemplary embodiments of the present invention include a substrate; a platinum (Pt) layer formed on the substrate by electroplating; It provides an oxygen electrode comprising; an iridium oxide layer formed on the platinum (Pt) layer by electroplating.

4A to 4C, the prior art uses iridium oxide supported on platinum or a platinum catalyst supported on iridium oxide, an electrode that raises platinum by a spray method after iridium oxide plating, for example, an oxygen generating catalyst, an oxygen reduction catalyst, both spray ( 4a), after oxygen generation catalyst plating, oxygen reduction catalyst spray (FIG. 4b) was developed and the catalyst layer was mainly formed by a spray method, but in this case, an excess of catalyst (eg, 1-3 mg/cm ² ) There was a problem in that the amount of precious metal that was used and lost was large.

On the contrary, the present inventors used double plating when forming the catalyst layer of the oxygen electrode (FIG. 4c), and electroplated the oxygen generating catalyst on the electroplated oxygen reduction catalyst, and both platinum and iridium oxide (iridium oxide) are small. By increasing the loading and forming a catalyst layer that is chemically bonded to each other at the same time, a technology with excellent fuel cell and water electrolysis performance due to synergistic effect was developed.

Specifically, in the oxygen electrode of the present invention, when the catalyst layer (platinum (Pt) layer and iridium oxide layer is formed on the substrate, unlike the spray method, it is supported (electroplating) by electrochemical reaction rather than physical bonding with the substrate, so that the contact resistance It contributes to the reduction, and it is possible to support a nanometer-level thin catalyst layer on the substrate during electroplating, and it is possible to obtain a high catalyst activity with a small loading amount by reducing the lost catalyst active area, and to control the catalyst loading amount according to the plating conditions Easy.

In a non-limiting example, the substrate may have a porosity of 60% as a gas diffusion layer.

In example embodiments, the oxygen electrode may be for a water electrolysis device or for a regenerative fuel cell.

In example embodiments, the platinum (Pt) layer is platinum (Pt). The particles may be attached (or deposited) on the substrate. Specifically, the platinum (Pt) The layer covers the substrate surface, preferably covering such that the substrate material is not exposed. In other words, the preferred structure is a platinum (Pt) substrate surface. It is an exposure free structure with a layer covering but no substrate material exposure.

In example embodiments, the iridium oxide layer may include iridium oxide particles surrounding the platinum (Pt) layer or platinum (Pt) particles. Specifically, when the iridium oxide layer is formed on the platinum (Pt) layer by electroplating, the platinum (Pt) layer or the platinum (Pt) particles are surrounded by iridium oxide particles, and are not physically bonded to each other but in an electrochemical reaction. It may be in the form of a catalyst bound by the Accordingly, the surface area of the iridium oxide is increased to increase the water electrolysis performance.

The chemical formula of the iridium oxide may be IrO _X , and x may be 1.5 to 2.5.

In a non-limiting example, the surface area of the iridium oxide may be 25 to 200 cm ² /cm ² _geo .

In a non-limiting example, the platinum (Pt) The thickness of the layer is 0.01-1.2 μm, preferably 10-500 nm, and platinum (Pt) The particle size is 3-20 nm, preferably 5-10 nm.

In a non-limiting example, the iridium oxide The thickness of the layer is 0.01-1 μm, preferably 10-100 nm, iridium oxide The particle size is 1 to 10 nm, preferably 1.5 to 2 nm.

In example embodiments, the weight of the platinum (Pt) layer may be 0.05 to 0.5 mg/cm ² . If the weight of platinum is less than 0.05 mg/cm ² , there may be a decrease in performance in the fuel cell mode, and if it is more than 0.5 mg/cm ² , there may be a decrease in catalytic activity per mass in the water electrolysis mode.

In example embodiments, the total weight of the platinum (Pt) layer and the iridium oxide layer may be 0.1 to 1.0 mg/cm ² . When the total weight is less than 0.1 mg/cm ² , there may be a decrease in performance in the fuel cell mode, and when it exceeds 1.0 mg/cm ² , there may be a decrease in catalytic activity per mass in the water electrolysis mode.

In exemplary embodiments, the substrate may be titanium paper made of titanium fibers. Previously reported electrodes have a carbon corrosion problem by using a carbon material as a substrate, but in the present invention, titanium can be used to increase the stability of the electrode.

In example embodiments, the oxygen electrode may be used in a regenerative fuel cell operated at a current density of 0.1 A/cm ² or more.

In exemplary embodiments of the present invention, a water electrolysis device including the above-described oxygen electrode is provided.

In exemplary embodiments of the present invention, there is provided a regenerative fuel cell including the above-described oxygen electrode.

In example embodiments, the regenerative fuel cell may be an integrated regenerative fuel cell.

Oxygen electrode manufacturing method

In exemplary embodiments of the present invention, there is provided a method for manufacturing the above-described oxygen electrode, comprising: forming a platinum (Pt) layer on a substrate by electroplating; and forming an iridium oxide layer on the platinum (Pt) layer by electroplating.

Referring to FIG. 3A , the conventional electrode manufacturing method is composed of a catalyst, an ionomer solution, isopropyl alcohol, and water, and a slurry containing the catalyst is prepared and a sonication spray gun is used for 1 hour on the substrate by a target amount. It is a spray method.

On the other hand, referring to FIG. 3b, the oxygen electrode of the present invention forms a platinum (Pt) layer and an iridium oxide layer by electroplating differently from the spray method, so that it is supported by an electrochemical reaction rather than a physical bonding with the substrate, During plating, a nanometer-level thin catalyst layer can be supported on the substrate, and the loss of catalyst active area is reduced, so that high catalyst activity can be obtained with a small loading amount, and it is easy to control the catalyst loading amount according to the plating conditions.

In example embodiments, in forming a platinum (Pt) layer on the substrate by electroplating, at least one of a plating current and a plating time may be adjusted.

In exemplary embodiments, in the step of forming a platinum (Pt) layer on the substrate by electroplating, the plating current may be -100 mA cm ^-2 to -5 mA cm ^-2 , for example, -50 mA cm ^-2 to -5 mA cm ^-2 or preferably -10 mA cm ^-2 .

In exemplary embodiments, in the step of forming a platinum (Pt) layer on the substrate by electroplating, the plating time may be 30 seconds to 10 minutes, preferably 5 minutes to 8 minutes. If the plating time is less than 30 seconds, plating may not be sufficiently performed, and if the plating time is longer than 10 minutes, the performance does not increase in proportion to the amount of noble metal any more, so unnecessary costs may be spent.

The present invention will be described in more detail through the following practice. However, the examples are for illustrative purposes only, and the scope of the present invention is not limited thereto.

{Example}

Example 1. Oxygen electrode preparation: Platinum (Pt) layer plating on Ti paper (250 μm, Bekaert)

Chloroplatinic acid hydrate (99.995%, sigma aldrich) was added to a 0.5 MH ₂ SO ₄ solution and sonic was performed for 30 minutes. Before plating, titanium paper was acid-treated in an oxalic acid solution at 60° C. for 30 minutes. After that, a constant current was passed at 10 mA/cm ² and plating was performed. The plating time was adjusted to 30 seconds, 1 minute, 2 minutes, 5 minutes, 8 minutes and 10 minutes.

Example 2. Oxygen Electrode Fabrication: Iridium Oxide Layer Plating

Iridium chloride hydrate (IrCl ₄ ·H ₂ O), oxalic acid ((COOH) ₂ ·2H ₂ O), hydrogen peroxide (35%) in deionized water (DI water) H ₂ O ₂ ) and potassium carbonate (anhydrous potassium carbonate) were added thereto, and magnetic stirring was performed for 3 days. Then, on the electrode on which the platinum (Pt) layer prepared in Example 1 was plated, plating was performed for 10 minutes under the condition of 0.7 V (vs. SCE).

Example 3. Hydrogen Electrode Preparation: Pt/C Spray

A slurry for loading the catalyst on the electrode was prepared as follows. 46.2 wt% Pt/C, distilled water (DI water), 5 wt% nafion solution, and isopropanol were added, and sonication was performed for 1 hour. After that, spraying was carried out so that the weight of 0.4 mg/cm ² went up on 0BC (SGL carbon Ltd.).

Example 4. Fabrication of an integrated regenerative fuel cell

To fabricate a membrane electrode assembly (MEA), the hydrogen electrode, Nafion 212, and oxygen electrode were sequentially stacked, and hot pressing was performed at 120° C. for 1 minute at a pressure of 2.7 Mpa. Thereafter, the cell was tightened with 80 Lbin.

Example 5. Integrated Renewable Fuel Cell Performance Evaluation

During the water electrolysis operation, distilled water (DI water) was supplied to the oxygen electrode at a rate of 15 ml/min at a cell temperature of 80°C. In the hydrogen electrode, the gas inlet was blocked to prevent gas from entering from the outside. Performance was measured for 1 minute at each voltage while raising the voltage by 0.5 V from 1.25 V to 2.0 V. The current density measured at each voltage is recorded once every 10 seconds, and the average value of this value was used to obtain the current density at each voltage.

During fuel cell operation, the cell temperature was maintained at 80°C, the same as in water electrolysis, and the supplied fuel was adjusted to a temperature of 70°C. Oxygen was supplied to the oxygen electrode at a rate of 400 ccm, and hydrogen was supplied to the hydrogen electrode at a rate of 400 ccm. Performance was measured from OCV condition to 0.2 V.

comparative example

An integrated regenerative fuel cell was manufactured in the same manner as in Example except that an iridium oxide layer or a platinum (Pt) layer was solely electroplated when the oxygen electrode was manufactured (ED-iridium oxide/Ti, ED-Pt/Ti).

In addition, in the case of manufacturing the oxygen electrode, after electroplating the iridium oxide layer on the substrate of the oxygen electrode, a platinum (Pt) layer was formed on the iridium oxide layer by a spray method, except for the same as in the embodiment. A regenerative fuel cell was prepared (spray-Pt/ED-iridium oxide/Ti).

test example

First, FIGS. 5A to 5C show an oxygen electrode 5a in which an iridium oxide layer is electroplated on a substrate, and an oxygen electrode 5b in which a platinum (Pt) layer is electroplated on a substrate, respectively, in embodiments of the present invention. and a scanning microscope photograph of the surface of the oxygen electrode 5c on which a platinum (Pt) layer and an iridium oxide layer are sequentially electroplated on a substrate. Referring to this, in the case of the oxygen electrode 5c in which a platinum (Pt) layer and an iridium oxide layer are sequentially electroplated, it can be seen that the surface area is wide and the surface is rough compared to the others.

6A, 6B, and Table 1 below show that in Examples and Comparative Examples of the present invention, when the plating time of iridium oxide is the same, the fuel cell and water electrolysis according to the electroplating time of the platinum (Pt) layer of the oxygen electrode This is a graph showing the performance of Referring to this, it can be seen that although the fuel cell performance increases as the platinum plating time increases, the fuel cell performance does not significantly increase beyond a certain amount.

In particular, referring to FIG. 6B , as compared to the case where the iridium oxide layer is plated on the platinum-plated electrode (ED-IrOx w/o Pt), the iridium oxide layer is plated on the platinum-plated electrode, It can be seen that the performance increases rapidly. In addition, it can be confirmed that after a certain platinum plating time, the increase in water electrolysis performance does not occur significantly.

Pt _avg.
/mg cm ^-2 Ir _avg.
/mg cm ^-2 Total
/mg cm ^-2 Current Density at 0.6 V
/A cm ^-2 Current Density at 1.9 V
/A cm ^-2 ED-IrOx w/o Pt 0 0.150 0.150 0.014 2.29 ED-IrOx on
DC-Pt 30 s 0.079 0.063 0.142 0.004 3.22 ED-IrOx onDC-Pt 1 min 0.136 0.075 0.211 0.005 3.69 ED-IrOx onDC-Pt 2 min 0.168 0.170 0.338 0.146 5.00 ED-IrOx onDC-Pt 5 min 0.277 0.157 0.434 0.316 5.57 ED-IrOx onDC-Pt 8 min 0.417 0.198 0.615 0.245 5.41 ED-IrOx onDC-Pt 10 min 0.661 0.255 0.916 0.392 5.60

7A and 7B show the performance of water electrolysis of the double plating electrode according to the platinum (Pt) layer loading amount of the oxygen electrode ( FIG. 7A ) and the total noble metal catalyst loading amount in the oxygen electrode in Examples and Comparative Examples of the present invention It is a graph showing the performance of water electrolysis according to (Fig. 7b). Referring to this, it can be seen that the water electrolysis performance does not increase significantly above a specific platinum loading amount, and sufficient performance is exhibited even with a small amount of platinum (Pt) of about 0.3 mg/cm ² . Specifically, comparing 5 minutes, 8 minutes, and 10 minutes, it can be seen that the effect of increasing the platinum loading is no longer proportional and there is almost no increase rate. 8 is a diagram illustrating a case in which only a platinum (Pt) layer is electroplated on a substrate of an oxygen electrode, only an iridium oxide layer is electroplated, and a platinum (Pt) layer and an iridium oxide layer on the substrate in Examples and Comparative Examples of the present invention; It is a graph showing the water electrolysis performance in the case of electroplating sequentially. Platinum (Pt) layers were plated for 5 minutes each. Referring to this, when only the platinum (Pt) layer is electroplated on the substrate of the oxygen electrode, the water electrolysis performance hardly appears, but when iridium oxide is plated on the platinum-plated electrode than the iridium oxide-plated electrode in the absence of plated platinum It can be seen that the water electrolysis performance is rapidly increased. In addition, it can be seen that the current density increased more than 2.4 times from about 2.9 A/cm ² to 7.1 A/cm ² at 2.0 V.

9 is a case in which a platinum (Pt) layer and an iridium oxide layer are sequentially electroplated on the substrate of the oxygen electrode when the loading amount of the electroplated iridium oxide is the same in Examples and Comparative Examples of the present invention, and the oxygen electrode It is a graph showing the fuel cell performance when a platinum (Pt) layer is formed on the iridium oxide layer by a spray method after electroplating the iridium oxide layer on the substrate.

Referring to this, although the weight of plated iridium oxide is similar to 0.15-0.2 mg/cm ² , it can be confirmed that the water electrolysis performance is doubled, and when viewed from the data of FIG. It is thought that the electrolysis performance is not. In addition, it can be confirmed that the fuel cell performance is also increased by about 2 times compared to the platinum catalyst electrode of a similar amount raised by the spray method.

In addition, the water electrolysis operation current per catalyst mass corresponding to 50% of the URFC's circulation efficiency is 5.6816 A/mg (1.7 V), and the fuel cell operation current per catalyst mass is 0.0294 A/mg (0.85 V). The product of the water electrolysis operation current per catalyst mass and the fuel cell operation current at 50% circulation efficiency of the renewable fuel cell is 0.171 (A/mg) ² .

10 is a graph showing the circulation efficiency of the integrated renewable fuel cell at a similar catalyst loading amount in Examples and Comparative Examples (reference 1-4) of the present invention. In particular, [Reference 1] 2016 Int. J. Hydro. energy, 41, 20650-20659, [Reference 2] 2012 Int. J. Hydro. Energy, 37, 13522-13528, [Reference 3] 2011 Electrochimica Acta, 56, 4287-4293, [Reference 4] 2012 J. Power Sources., 198, 23-29 compared with URFC studies using Ti GDL. , it can be confirmed that, compared to previous studies, higher cycling efficiency with a similar catalyst loading amount, and similar cycling efficiency with a noble metal catalyst content that is more than twice less than the high catalyst loading in previous studies.

Claims (12)

A method for manufacturing an oxygen electrode, comprising:
forming a platinum (Pt) layer on the substrate by electroplating; and
Including; forming an iridium oxide layer on the platinum (Pt) layer by electroplating;
In the step of forming a platinum (Pt) layer on the substrate by electroplating, the plating time is more than 2 minutes to less than 8 minutes,
In the oxygen electrode,
The iridium oxide layer has a rough surface structure,
The weight of the platinum (Pt) layer is greater than 0.168 mg/cm ² to less than 0.417 mg/cm ² ,
The method of manufacturing an oxygen electrode, characterized in that the total weight of the platinum (Pt) layer and the iridium oxide layer is greater than 0.338 mg/cm ² to less than 0.615 mg/cm ² . The method of claim 1,
In the step of forming a platinum (Pt) layer on the substrate by electroplating, the plating current density is -100 mA cm ^-2 to -5 mA cm ^-2 , characterized in that the oxygen electrode manufacturing method. As an oxygen electrode manufactured by the manufacturing method of claim 1 or 2,
Board;
a platinum (Pt) layer formed on the substrate by electroplating; and
Including; an iridium oxide layer formed by electroplating on the platinum (Pt) layer,
The iridium oxide layer has a rough surface structure,
The weight of the platinum (Pt) layer is greater than 0.168 mg/cm ² to less than 0.417 mg/cm ² ,
Oxygen electrode, characterized in that the total weight of the platinum (Pt) layer and the iridium oxide layer is greater than 0.338 mg/cm ² and less than 0.615 mg/cm ² . 4. The method of claim 3,
The oxygen electrode, characterized in that for a water electrolysis device, oxygen electrode. 4. The method of claim 3,
The oxygen electrode is characterized in that for a regenerative fuel cell, oxygen electrode. 4. The method of claim 3,
The platinum (Pt) layer is platinum (Pt) An oxygen electrode, characterized in that particles are deposited on the substrate. 7. The method of claim 6,
The iridium oxide layer is characterized in that iridium oxide particles surround the platinum (Pt) particles. 4. The method of claim 3,
The substrate is an oxygen electrode, characterized in that the titanium paper made of titanium fibers. 4. The method of claim 3,
The oxygen electrode is an oxygen electrode, characterized in that used in a regenerative fuel cell operated at a current density of 0.1 A/cm ² or more. A water electrolysis device comprising the oxygen electrode according to claim 4 . A regenerative fuel cell comprising the oxygen electrode according to claim 5 . 12. The method of claim 11,
The regenerative fuel cell is a regenerative fuel cell, characterized in that it is an integrated regenerative fuel cell.

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