Multi-layered water electrolysis electrode and manufacturing method therefor

Abstract

The present invention relates to a multi-layered water electrolysis electrode and a manufacturing method therefor. The water electrolysis electrode comprises: a first porous nickel support; a sintered metal layer; and a second porous nickel support. The method for manufacturing a water electrolysis electrode comprises the steps of: applying metal powder to a first porous nickel support; laminating a second porous nickel support on the surface to which the metal powder is applied, to manufacture a laminate; compressing the laminate; and heat-treating the compressed laminate in a reducing atmosphere. The method for manufacturing a water electrolysis electrode comprises the steps of: providing a catalyst-coated first porous nickel support and a catalyst-coated second porous nickel support; compressing and molding metal powder and then heat-treating same in a reducing atmosphere to manufacture a sintered metal layer; and placing and compressing the sintered metal layer between the catalyst-coated first porous nickel support and the catalyst-coated second porous nickel support.

Description

Multilayered water electrolysis electrode and method for manufacturing the same

[0001] The present invention relates to a multilayer structured water electrolysis electrode and a method for manufacturing the same, and more specifically, to manufacturing a water electrolysis electrode of higher performance by providing a multilayer structured electrode by combining a metal sintered electrode and a metal foam-shaped electrode.

[0002] Efforts to reduce carbon dioxide emissions due to global warming and to use clean hydrogen as fuel are being made worldwide, and in particular, water electrolysis technology, which produces green hydrogen by electrolyzing water using renewable energy, is gaining attention as the most desirable method for producing clean hydrogen.

[0003] Methods used for water electrolysis include high-temperature electrolysis, which produces hydrogen by decomposing steam under high-temperature operating conditions, and low-temperature electrolysis, which decomposes water at low temperatures. Since high-temperature electrolysis operates at temperatures exceeding 700°C, it presents a high level of technical difficulty, and thus, it can be considered to be in the early stages of commercialization. Although there are concerns regarding the use of precious metals such as Pt and Ir as electrode catalysts and a short lifespan due to strong corrosiveness, a low-temperature electrolysis technology known as polymer electrolyte electrolysis, commercialization has recently begun. Meanwhile, alkaline electrolysis is a method in which electrodes come into contact with an alkaline electrolyte to electrolyze water. It has the advantages of not requiring the use of expensive precious metals, operating at low temperatures, making manufacturing and maintenance relatively easy, and having low equipment costs; consequently, it has been commercialized for a long time, with the largest capacity facilities distributed worldwide.

[0004] The electrode material used in such alkaline water electrolysis is most commonly nickel, which is stable even in high-concentration alkaline aqueous solutions, and nickel-plated stainless steel is also used. Various electrode shapes are widely used, such as plate, mesh, porous plate, and foam types. A method to increase the specific surface area of ​​nickel is disclosed, for example, by alloying nickel with aluminum, then leaching the aluminum in an alkaline solution to produce a material with a larger nickel surface area, and subsequently manufacturing a porous nickel or nickel alloy electrode by performing tape casting and heat treatment therefrom (Korean Registered Patent No. 10-2243511).

[0005] In alkaline water electrolysis, the electrolyte containing hydroxide ions (OH-) moves through the membrane, but there is a problem in that the gas generated along with it also moves to the opposite electrode. In particular, hydrogen gas moves relatively toward the oxygen generating electrode, causing oxygen and hydrogen to mix; if the amount of mixing increases, there is a risk of explosion, so careful management is required in water electrolysis.

[0006] [Prior Art Literature]

[0007] [Patent Document](Patent Document 1) Republic of Korea Registered Patent No. 10-2243511

[0008] According to one embodiment of the present invention, an electrode capable of providing improved water electrolysis performance may be provided.

[0009] According to another embodiment of the present invention, a method for manufacturing an electrode capable of providing improved water electrolysis performance may be provided.

[0010] The problems of the present invention are not limited to those described above. A person skilled in the art to which the present invention pertains will have no difficulty understanding additional problems of the present invention from the overall contents of this specification.

[0011] A water electrolysis electrode according to one embodiment of the present invention is a water electrolysis electrode comprising a first porous nickel support; a sintered metal layer; and a second porous nickel support.

[0012] The first porous nickel support and the second porous nickel support may each be one or more types independently selected from the group consisting of nickel foam, nickel mesh, nickel felt, and nickel woven fabric.

[0013] The above sintered metal layer may be a sintered metal electrode layer in which metal powder is compressed and heat-treated in a reducing atmosphere.

[0014] The metal of the above-mentioned sintered metal layer may be one or more selected from the group consisting of cobalt (Co), iron (Fe), molybdenum (Mo), copper (Cu), and nickel (Ni).

[0015] At least one of the first porous nickel support and the second porous nickel support may be coated with Raney-type nickel consisting of a Ni-Al alloy layer.

[0016] The total thickness of the electrode may be 0.2 mm to 1 mm.

[0017] The thickness ratio of the first porous nickel support, the sintered metal layer, and the second porous nickel support may be 10 to 30:40 to 80:10 to 30.

[0018] A method for manufacturing a water electrolysis electrode according to another embodiment of the present invention comprises the steps of: applying metal powder to a first porous nickel support; manufacturing a laminate by laminating a second porous nickel support onto the surface coated with metal powder; and compressing the laminate.

[0019] A method for manufacturing a water electrolysis electrode may include the step of heat-treating a compressed laminate in a reducing atmosphere.

[0020] The step of applying the metal powder involves applying metal powder having a particle size of 1 to 10 μm at a rate of 0.06 to 0.15 g / cm³ 2 It may be applied in an amount of

[0021] The above pressing step is 100 to 900 kg / cm² 2 It may be performed within the pressure range.

[0022] The heat treatment step may be performed in a temperature range of 650 to 950°C.

[0023] A method for manufacturing a water electrolysis electrode according to another embodiment of the present invention may be a method for manufacturing a water electrolysis electrode comprising the steps of: providing a catalyst-coated first porous nickel support and a catalyst-coated second porous nickel support; forming a metal powder by pressing and then heat-treating it in a reducing atmosphere to produce a sintered metal layer; and placing the sintered metal layer between the catalyst-coated first porous nickel support and the catalyst-coated second porous nickel support and pressing it.

[0024] The heat treatment step may be performed in a temperature range of 650 to 950°C.

[0025] The compression step is 100 to 900 kg / cm² 2 It may be performed within the pressure range.

[0026] According to the present invention, an electrode comprising a composite layer including a sintered metal and a nickel porous layer is provided, and the electrode of the present invention allows gas generated from the electrode to pass easily while maintaining excellent electrode strength, thereby enabling improved water electrolysis performance.

[0027] Figure 1 shows a photograph of the nickel powder used in the example.

[0028] Figure 2 schematically shows the electrode of the composite layer structure of Example 1.

[0029] Figure 3 is a scanning electron microscope image of the fracture surface of the electrode of Example 1, taken at magnifications of ×100 and ×1000, respectively.

[0030] Figure 4 is a scanning electron microscope image of the surface of the electrode of Example 1 taken at magnifications of ×50 and ×200, respectively.

[0031] Figure 5 schematically shows the stacked form of a nickel foam electrode coated with a catalyst and a nickel sintered electrode during the electrode manufacturing process according to Example 2.

[0032] Figure 6 is a scanning electron microscope image of the fracture surface of the electrode of Example 2, taken at magnifications of ×100 and ×1000, respectively.

[0033] Figure 7 is a scanning electron microscope image of the surface of the electrode of Example 2 at magnifications of ×50 and ×200, respectively.

[0034] Figure 8 is a graph showing the results of comparing the hydrogen generation activity of Comparative Example 1, Comparative Example 2, and Example 1.

[0035] FIG. 9 is a graph showing the results of comparing the hydrogen generation activity of Comparative Example 1-1, Comparative Example 2-1, and Comparative Example 3; and Example 2.

[0036] Preferred embodiments of the present invention will be described below with reference to the attached drawings. However, embodiments of the present invention may be modified in various other forms, and the scope of the present invention is not limited to the embodiments described below.

[0037] In addition, embodiments of the present invention are provided to more fully explain the present invention to those with average knowledge in the relevant technical field.

[0038] In drawings, the shapes and sizes of elements may be exaggerated for clearer explanation.

[0039] In describing the embodiments of the present invention, if it is determined that a detailed description of known technology related to the present invention may unnecessarily obscure the essence of the present invention, such detailed description will be omitted. Furthermore, the terms described below are defined considering their functions in the present invention, and these may vary depending on the intentions or conventions of the user or operator. Therefore, such definitions should be based on the content throughout this specification. The terms used in the detailed description are merely for describing the embodiments of the present invention and should not be limited in any way. Unless explicitly stated otherwise, expressions in the singular form include the meaning of the plural form.

[0040] In this description, expressions such as “include” or “equipped” are intended to refer to certain characteristics, numbers, steps, actions, elements, parts or combinations thereof, and should not be interpreted to exclude the existence or possibility of one or more other characteristics, numbers, steps, actions, elements, parts or combinations thereof other than those described.

[0041] Unless otherwise specifically defined in the specification of the present invention, % units mean weight %.

[0042] Additionally, throughout the specification, when it is said that one part is 'connected' to another part, this includes not only cases where they are 'directly connected,' but also cases where they are 'indirectly connected' with other elements in between.

[0043] The present invention will be described in detail below through each embodiment or example of the invention. It should be noted that each embodiment or example described in this specification is not limited to a single embodiment or example, but may also be combined with other embodiments or examples. Accordingly, the citation of claims in the patent claims is merely an example of an embodiment, and the technical concept of the present invention should not be interpreted as being limited only to a combination with the cited claims; rather, combinations with various claims are also included within the scope of the technical concept of the present invention.

[0044] Description of the invention

[0045] According to the present invention, an electrode having a multilayer structure in which a metal sintered electrode and a metal foam-shaped electrode are combined, which can be used as an alkaline water electrolysis electrode, and a method for manufacturing the same are provided.

[0046] More specifically, the water electrolysis electrode of the present invention comprises a first porous nickel support; a sintered metal layer; and a second porous nickel support.

[0047] The above sintered metal layer may be a sintered metal electrode layer in which metal powder is compressed and heat-treated in a reducing atmosphere. In this case, the metal of the above sintered metal layer may be one or more selected from the group consisting of cobalt (Co), iron (Fe), molybdenum (Mo), copper (Cu), and nickel (Ni), and preferably nickel.

[0048] In the case of a metal sintered electrode consisting only of a sintered metal layer, the pore size is small due to the characteristics of manufacturing by sintering fine metal powder, making it difficult for gas generated from the electrode to pass through, which may result in a decrease in the efficiency of the electrode. Therefore, to facilitate the passage of gas, it is advantageous for the electrode thickness to be thin, but if it is too thin, there is a problem that the electrode strength is insufficient and it is difficult to handle.

[0049] Accordingly, in the present invention, for the formation of a sintered metal layer, a metal powder having a particle size of 1 to 10 μm is used at a concentration of 0.06 to 0.15 g / cm³ 2 , for example, 0.08 to 0.14 g / cm³ 2 , 0.1 to 0.13 g / cm³ 2 A sintered metal layer can be manufactured by applying an amount of [amount] and then pressing and sintering.

[0050] In the present invention, to compensate for the disadvantages of the sintered metal layer described above, a porous nickel support is placed on one or both sides of the sintered metal layer to form an electrode.

[0051] The porous nickel support may have a pore size of 200 to 500 μm, for example 300 to 480 μm, or 400 to 470 μm, and a thickness of 1 to 3 mm, for example 1.1 to 2.5 mm, or 1.2 to 2 mm, but may be used without limitation as long as it has a large surface area per unit volume and mechanical strength suitable for use as an electrode. Nickel foam, nickel felt, nickel woven fabric, etc. may be used as such a porous nickel support.

[0052] More specifically, the first porous nickel support and the second porous nickel support may each be one or more selected from the group consisting of nickel foam, nickel mesh, nickel felt, and nickel woven fabric, and may be, for example, nickel foam, although not particularly limited thereto.

[0053] Furthermore, when using the porous nickel support, for example, nickel foam as a substrate, the specific surface area can be increased, and a catalyst material with superior activity to nickel can be coated and used. For example, at least one of the first porous nickel support and the second porous nickel support may be coated with Raney nickel obtained by Al PVD coating, heat treatment, and removal of Al in an alkaline solution.

[0054] The total thickness of the water electrolysis electrode according to the present invention may be 0.2 mm to 1 mm, for example, 0.3 to 0.7 mm.

[0055] Meanwhile, when the water electrolysis electrode of the present invention comprises three layers of a first porous nickel support, a sintered metal layer, and a second porous nickel support, the thickness of the region where the sintered metal layer is formed may be 30 to 80% of the total thickness, and for example, the thickness ratio of the first porous nickel support, the sintered metal layer, and the second porous nickel support may be 10 to 35 : 30 to 80 : 10 to 35 or 15 to 30 : 40 to 70 : 15 to 30.

[0056] If the thickness ratio of the sintered metal layer exceeds the above range, there may be a problem where the efficiency of the electrode decreases because the generated gas is difficult to pass through, and if it is below the above range, there may be a problem where the strength of the electrode becomes insufficient.

[0057] The above-described method for manufacturing a water electrolysis electrode of the present invention may include the steps of: applying metal powder to a first porous nickel support; manufacturing a laminate by laminating a second porous nickel support on the surface coated with metal powder; compressing the laminate; and heat-treating the compressed laminate in a reducing atmosphere.

[0058] The step of applying metal powder to the first porous nickel support involves applying metal powder having a particle size of 1 to 10 μm at a rate of 0.06 to 0.15 g / cm³ 2 , for example, 0.08 to 0.14 g / cm³ 2 , 0.1 to 0.13 g / cm³ 2 It may be applied in an amount of

[0059] After that, a step of manufacturing a laminate is performed by laminating a second porous nickel support onto a surface coated with metal powder.

[0060] Subsequently, the step of compressing the laminate; and the step of heat-treating the compressed laminate in a reducing atmosphere are performed, wherein the compressing step may be performed sequentially or simultaneously.

[0061] The above pressing step is 100 to 900 kg / cm² 2 It may be performed within a pressure range of, for example, 150 to 700 kg / cm² 2 , preferably 200 to 500 kg / cm² 2 It is performed within the pressure range.

[0062] Meanwhile, the heat treatment step may be performed in a temperature range of 650 to 950°C, for example, in a temperature range of 700 to 850°C. Sintering may be performed by the heat treatment step, and if the sintering is performed at a temperature below 650°C, the bonding force between nickel powder particles may be insufficient, and if performed at a temperature exceeding 950°C, the pore size may be reduced.

[0063] The above heat treatment step may be performed in a reducing atmosphere, and the reducing atmosphere may be an atmosphere containing hydrogen (H₂) gas, for example, under an inert mixed gas containing 5 to 40 v / v% or 10 to 30 v / v% of hydrogen. The inert gas may be, for example, argon, but is not limited thereto.

[0064] Meanwhile, in the present invention, the porous nickel support may be coated with a catalyst, and in the present invention, the 'catalyst' includes all materials capable of improving the activity of the electrode, and the 'coating' is also not particularly limited to the coating method and is intended to include all cases where part or all of the porous nickel support is coated.

[0065] The above coating includes not only cases where it is coated by at least one of the methods of physical vapor deposition (PVD), chemical vapor deposition, electro-deposition, dip coating, spray coating, and electrophoresis coating, but also cases where it is treated with plasma, and further includes all cases where any component other than the electrode material is formed on the electrode surface by including at least one step among heat treatment, leaching, and reduction.

[0066] In the method for manufacturing a water electrolysis electrode comprising a catalyst-coated porous nickel support as described above, heat treatment may not be performed depending on the catalyst material. For example, if a Ni-Al coating layer is formed on the electrode surface, heat treatment may be omitted because performance degradation may occur.

[0067] More specifically, a method for manufacturing a water electrolysis electrode comprising a catalyst-coated porous nickel support may include the steps of: providing a catalyst-coated first porous nickel support and a catalyst-coated second porous nickel support; forming a metal powder by pressing and then heat-treating it in a reducing atmosphere to produce a sintered metal layer; and placing the sintered metal layer between the catalyst-coated first porous nickel support and the catalyst-coated second porous nickel support and pressing it.

[0068] The heat treatment step may be performed in a temperature range of 650 to 950°C, for example, 700 to 900°C, and the pressing step may be 100 to 900 kg / cm² 2 For example, 150 to 700 kg / cm² 2 , preferably 200 to 500 kg / cm² 2 As described above, it can be performed within the pressure range.

[0069] At this time, the catalyst coating composition is also as described above, and when coated with a Raney-type porous composite containing nickel, it can be performed as follows.

[0070] First, a laminate is provided having a layer containing nickel (Ni) and a layer containing a second metal (M), wherein the layer containing nickel (Ni) may be a porous nickel support using at least one selected from the group consisting of a nickel plate, a nickel mesh, and nickel forms.

[0071] The second metal mentioned above may be aluminum (Al) or zinc (Zn).

[0072] For example, after forming a laminate, an alloy of nickel and a second metal is formed through heat treatment, wherein the heat treatment can be performed at a temperature of 400 to 700 °C, for example, 500 to 680 °C, for a time of more than 15 minutes and less than 90 minutes, for example, 30 minutes to 70 minutes. Next, selective leaching can be performed on the laminate after heat treatment to form a porous layer on the surface of the laminate.

[0073] Selective leaching means leaching only the second metal without leaching nickel. Selective leaching can be performed at room temperature, for example, at a temperature of 25°C to 90°C, for 2 to 24 hours. As the leaching solution used for selective leaching, 10 wt% KOH may be used, but the present invention is not limited thereto.

[0074] By performing a selective leaching step in this manner to form a porous layer, a coating layer composed of a Laney-type porous composite containing nickel and some second metal remaining can be formed.

[0075] The present invention will be described in detail below through examples. However, it should be noted that the examples described below are intended merely to illustrate and embody the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by the matters described in the patent claims and matters reasonably inferred therefrom.

[0076] Examples

[0077] 1. Manufacturing of electrodes

[0078] Example 1

[0079] A metal mold with a groove measuring 40 × 40 mm was prepared, and nickel foam cut to the same size was mounted on the bottom of the mold. The nickel foam used had a pore size of 0.45 mm, a thickness of 1.5 mm, and a density of 420 g / m³. 2 It was. 0.12 g / cm³ of pure nickel powder having a particle size of 1 µm to 10 µm, as shown in the photograph of Fig. 1, on the top of the nickel foam. 2 It was applied in the amount of... After additionally mounting the same nickel foam as above on top, a press was used at a pressing pressure of 350 kgf / cm² 2 The three-layer laminated electrode structure thus compressed was heat-treated and sintered in a reducing atmosphere. The heat treatment was carried out in a reducing atmosphere mixed with 10 v / v% hydrogen in argon, at a temperature of 750℃ and a holding time of 1 hour.

[0080] Through these steps, an electrode with a composite layer structure of Example 1 having a structure as shown in Fig. 2 was fabricated.

[0081] Figure 3 is a scanning electron microscope image of the fracture surface of the electrode of Example 1 taken at magnifications of ×100 and ×1000, respectively. The thickness of the electrode of Example 1 was approximately 0.6 mm, and it can be confirmed that there is a metal sintered body with fine pores in the center.

[0082] Figure 4 is a scanning electron microscope image of the surface of the electrode of Example 1 taken at magnifications of ×50 and ×200, respectively, showing that the surface is exposed to compressed nickel foam, and in the high-magnification image on the right, a metal sintered layer can be seen inside the space of the nickel foam.

[0083] Example 2

[0084] In this embodiment, a metal sintered electrode and a catalyst-coated nickel foam electrode were prepared, a metal mold having a groove of 40 x 40 mm was prepared, the catalyst-coated nickel foam electrode cut to the same size was mounted on the bottom of the mold, the metal sintered electrode was mounted on the top of the nickel foam, and the catalyst-coated nickel foam was additionally mounted on top of the metal sintered electrode, and then an electrode of Example 2 having a size of 40 mm × 40 mm was produced using a press.

[0085] In Example 2, the same nickel powder as in Example 1 was used, and this nickel powder was placed in a 40 × 40 mm mold at a concentration of 0.13 g / cm³ 2 Put in the amount of 350 kg / cm² 2 A metal sintered electrode was fabricated by forming it under pressure and then performing heat treatment at 650°C for 1 hour in a reducing atmosphere mixed with 10 v / v% hydrogen in argon.

[0086] Meanwhile, the catalyst-coated nickel foam increased the specific surface area of ​​nickel by forming a Raney alloy phase through heat treatment and Al leaching processes after physically depositing Al onto the nickel foam.

[0087] More specifically, 4 x 4 cm 2 A nickel foam of a certain size was cleaned, and a laminate was fabricated by depositing aluminum onto the nickel foam using PVD sputtering. The average thickness of the deposited aluminum layer was 2 μm. The laminate was heat-treated at 610 °C for 30 minutes and then cooled to room temperature. To create a porous layer, Al was leached by chemical leaching at 80 °C for 12 hours using a leaching solution (30 wt% KOH). Through this process, a nickel foam electrode coated with a Raney-type porous Ni-Al catalyst was obtained.

[0088] After stacking the catalyst-coated nickel foam electrode and the nickel sintered electrode prepared in this manner as shown in Fig. 5, 350 kg / cm²2 It was compressed under pressure and no separate heat treatment was performed. This is because, in the case of the catalyst-coated nickel foam applied in Example 2, additional heat treatment could alter the properties of the Ni-Al coating layer formed on the surface, leading to performance degradation. For this reason, heat treatment was not performed during the manufacture of the composite layer electrode in Example 2, but subsequent heat treatment may be performed if it does not affect the performance of the catalyst-coated nickel foam or if the activity of the catalyst is improved.

[0089] Figure 6 is a scanning electron microscope image of the fracture surface of the electrode of Example 2 at magnifications of ×100 and ×1000, respectively. The thickness of the electrode of Example 2 was approximately 0.6 mm, and it can be confirmed that there is a metal sintered electrode with fine pores in the center.

[0090] Figure 7 is a scanning electron microscope image of the surface of the electrode of Example 2 taken at magnifications of ×50 and ×200, respectively. The exposed surface is a nickel foam coated with a catalyst, and in the high-magnification image on the right, a metal sintered electrode can be seen inside the space of the nickel foam. In the case of the nickel foam coated with a Ni-Al alloy layer catalyst, some cracks may form during the molding process because the alloy layer is relatively brittle, but it was confirmed that this does not affect the performance of the electrode.

[0091] 2. Evaluation of Hydrogen Generation Characteristics

[0092] To evaluate the hydrogen generation characteristics of the composite layer electrode prepared according to Example 1, a potentiodynamic polarization test of the water electrolysis reaction in an alkaline aqueous solution was performed.

[0093] The electrode prepared under the conditions of Example 1 was used as the working electrode, a platinum electrode was used as the counter electrode, and an Ag / AgCl electrode was used as the reference electrode to construct a 3-electrode electrochemical cell and conduct the experiment.

[0094] A 30 wt% KOH aqueous solution at 70°C was used as the electrolyte. The potential applied to the graph was converted to RHE (Reversible Hydrogen Electrode) and plotted. To compare the relative effects of the fabricated electrodes, the performance of nickel foam was also compared, with a pore size of 450 µm, a thickness of 1.5 mm, and a yield of 420 g / m². 2 A commercial nickel foam having density specifications was used as Comparative Example 1.

[0095] Furthermore, to compare the compounding effect of the electrode, the same nickel powder used in Example 1 was used at a pressing pressure of 350 kg / cm² 2 The performance of a metal nickel sintered electrode prepared by heat treatment at a heat treatment temperature of 750℃ for 1 hour was evaluated together with Comparative Example 2.

[0096] Figure 9 is a graph showing the results of comparing the activity of hydrogen generation. When the same current density is applied, the closer the potential is to 0, the lower the overvoltage, which indicates superior performance. The electrode sintered from nickel powder in Comparative Example 2 is superior to the nickel foam in Comparative Example 1, and furthermore, in the case of Example 1, the best performance is shown by configuring the nickel foam and the nickel sintered electrode as a composite layer.

[0097] Table 1 below is for a current density of 100 mA / cm² 2 This compares the overvoltage of the electrode under the application conditions.

[0098] Electrode Classification Overvoltage (mV) Comparative Example 1 (Nickel Foam) 310 Comparative Example 2 (Nickel Sintered Electrode) 208 Example 1 172

[0099] The overpotential of the nickel foam in Comparative Example 1 is 310 mV, and that of the nickel sintered electrode in Comparative Example 2 is 208 mV. In the case of Example 1 of the present invention, which combines these, the overpotential is 172 mV, confirming that the water electrolysis performance has been improved. Meanwhile, Figure 9 is a graph showing the results of comparing the hydrogen generation activity of Example 2. When the same current density is applied, a potential closer to zero indicates a lower overpotential and superior performance; among the electrode compositions of Example 2 of the present invention, the nickel foam, nickel sintered electrode, catalyst-coated nickel foam, and Example 2 show progressively lower overpotentials. Table 2 is for a current density of 100 mA / cm² 2 This compares the overvoltage of the electrode under the application conditions.

[0100] Electrode Classification Overvoltage (mV) Comparative Example 1-1 (Nickel Foam) 333 Comparative Example 2-1 (Nickel Sintered Electrode) 163 Comparative Example 3 (Catalyst-Coated Nickel Foam) 122 Example 270

[0101] The overpotential of the nickel foam in Comparative Example 1-1 was 333mV, the nickel sintered electrode in Comparative Example 2-1 was 163mV, and the catalyst-coated nickel foam in Comparative Example 3 was 122mV; however, the electrode in Example 2 of the present invention showed a remarkably superior overpotential of 70mV, confirming that the water electrolysis performance is significantly improved compared to the existing technology.

[0102] [Explanation of the symbol]

[0103] 10 porous nickel support (nickel foam)

[0104] 20 sintered metal layer

[0105] 30 Coated porous nickel support (coated nickel foam)

Claims

1. A water electrolysis electrode comprising a first porous nickel support; a sintered metal layer; and a second porous nickel support.

2. The water electrolysis electrode according to claim 1, wherein the first porous nickel support and the second porous nickel support are each independently one or more selected from the group consisting of nickel foam, nickel mesh, nickel felt, and nickel woven fabric.

3. In claim 1, the water electrolysis electrode, wherein the sintered metal layer is a sintered metal electrode layer in which metal powder is compressed and heat-treated in a reducing atmosphere.

4. A water electrolysis electrode according to claim 1, wherein the metal of the sintered metal layer is one or more selected from the group consisting of cobalt (Co), iron (Fe), molybdenum (Mo), copper (Cu), and nickel (Ni).

5. In claim 1, a water electrolysis electrode coated with Raney-type nickel, wherein at least one of the first porous nickel support and the second porous nickel support is a Ni-Al alloy layer.

6. The water electrolysis electrode according to claim 1, wherein the total thickness of the electrode is 0.2 mm to 1 mm.

7. A water electrolysis electrode according to claim 1, wherein the thickness ratio of the first porous nickel support, the sintered metal layer, and the second porous nickel support is 10 to 35 : 30 to 80 : 10 to 35.

8. A step of applying metal powder to the first porous nickel support; A step of manufacturing a laminate by laminating a second porous nickel support onto a surface coated with metal powder; Step of compressing the above laminate; A step of heat-treating the compressed laminate in a reducing atmosphere; A method for manufacturing a water electrolysis electrode comprising 9. In claim 8, the step of applying the metal powder comprises 2 1 to 10 μm of metal powder at a particle size of 0.06 to 0.15 g / cm³ 2 A method for manufacturing a water electrolysis electrode, wherein the electrode is applied in an amount of 10. In claim 8, the pressing step is 100 to 900 kg / cm² 2 A method for manufacturing a water electrolysis electrode, performed within a pressure range.

11. In claim 8, the heat treatment step is performed in a temperature range of 650 to 950°C, Method for manufacturing a water electrolysis electrode.

12. A step of providing a catalyst-coated first porous nickel support and a catalyst-coated second porous nickel support; A step of preparing a sintered metal layer by compressing and molding metal powder and then heat-treating it in a reducing atmosphere; and A step of placing and pressing a sintered metal layer between a catalyst-coated first porous nickel support and a catalyst-coated second porous nickel support; A method for manufacturing a water electrolysis electrode comprising 13. In paragraph 12, the heat treatment step is performed in a temperature range of 650 to 950°C, Method for manufacturing a water electrolysis electrode.

14. In Paragraph 12, the compression step is 100 to 900 kg / cm² 2 A method for manufacturing a water electrolysis electrode, performed within a pressure range.

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