EP-4737614-A1 - ELECTRODE AND METHOD FOR MANUFACTURING ELECTRODE

Abstract

The present disclosure relates to an electrode and a method for preparing the same. According to the present disclosure, an electrode for anion exchange membrane water electrolysis that can achieve improved electrochemical performance and also has excellent durability can be provided.

Inventors

• CHAE, GYU SIK
• KIM, GIL HO
• CHO, YONG-HUN
• CHOI, HYUCK JAE

Assignees

• Hanwha Solutions Corporation

Dates

Publication Date

20260506

Application Date

20240805

Claims (16)

1. An electrode comprising: a metal substrate containing nickel; a first sol-gel coating layer formed on at least one surface of the metal substrate; and a second sol-gel coating layer formed on the first sol-gel layer, wherein the first sol-gel coating layer and the second sol-gel coating layer each independently comprise nickel and iron.
2. The electrode of claim 1, wherein: the metal substrate comprises a porous metal foam.
3. The electrode of claim 1, wherein: the first sol-gel coating layer and the second sol-gel coating layer each independently comprise nickel hydroxide and iron hydroxide.
4. The electrode of claim 1, wherein: the first sol-gel coating layer and the second sol-gel coating layer each independently exist in a state in which nickel hydroxide and iron hydroxide form a three-dimensional gel network structure.
5. The electrode of claim 1, wherein: the first sol-gel coating layer and the second sol-gel coating layer each independently comprise 10 to 25 moles of iron relative to 100 moles of the nickel.
6. The electrode of claim 1, wherein: the first sol-gel coating layer has a thickness of 100 to 200 nm.
7. The electrode of claim 1, wherein: the second sol-gel coating layer has a thickness of 500 to 2000 nm.
8. The electrode of claim 1, wherein: the thickness of the first sol-gel coating layer: the thickness of the second sol-gel coating layer is 1:2 to 1:10.
9. The electrode of claim 1, which is used for anion exchange membrane water electrolysis.
10. A method for preparing an electrode, comprising the steps of: preparing a first precursor solution(sol) containing a nickel precursor and an iron precursor; immersing a nickel substrate in the first precursor solution; inducing a sol-gel reaction in the first precursor solution to form a first sol-gel coating layer on the nickel substrate; preparing a second precursor solution(sol) containing a nickel precursor and an iron precursor; immersing a nickel substrate in the second precursor solution; and inducing a sol-gel reaction in the second precursor solution to form a second sol-gel coating layer on the nickel substrate.
11. The method for preparing an electrode of claim 10, wherein: the nickel precursor is a salt of nickel metal, which comprises at least one selected from the group consisting of a chlorine salt, a bromine salt, a sulfate salt, a nitrate salt, a carbonate salt, an acetate salt, a formic acid salt, an oxalic acid salt, and a citric acid salt.
12. The method for preparing an electrode of claim 10, wherein: the iron precursor is a salt of iron metal, which comprises at least one selected from the group consisting of a chlorine salt, a bromine salt, a sulfate salt, a nitrate salt, a carbonate salt, an acetate salt, a formic acid salt, an oxalic acid salt, and a citric acid salt.
13. The method for preparing an electrode of claim 10, further comprising stabilizing the formed first sol-gel coating layer, after forming the first sol-gel coating layer.
14. The method for preparing an electrode of claim 13, wherein: the stabilizing comprises at least one of the steps of: i) drying the electrode substrate on which the first sol-gel coating layer is formed, and ii) heat-treating the electrode substrate on which the first sol-gel coating layer is formed.
15. The method for preparing an electrode of claim 10, further comprising stabilizing the formed second sol-gel coating layer, after forming the second sol-gel coating layer.
16. The method for preparing an electrode of claim 15, wherein: the stabilizing comprises at least one of the steps of: i) drying the electrode substrate on which the second sol-gel coating layer is formed, and ii) heat-treating the electrode substrate on which the second sol-gel coating layer is formed.

Description

[TECHNICAL FIELD] CROSS-REFERENCE TO RELATED APPLICATION(S) This application claims the benefit of Korean Patent Application No. 10-2023-0103597 filed on August 8, 2023 with the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety. The present disclosure relates to an electrode and a method for preparing the electrode. [BACKGROUND] Due to the problems of depletion of fossil fuels and environmental pollution, the importance of environmentally friendly hydrogen production technologies has emerged. Accordingly, water electrolysis technologies are being actively studied, and representative low-temperature water electrolysis technologies may include proton exchange membrane water electrolysis(PEMWE), alkaline water electrolysis(AWE), anion exchange membrane water electrolysis(AEMWE), and the like. Alkaline water electrolysis has the advantage that relatively inexpensive non-platinum metals can be used. However, there is a problem that it requires highly corrosion-resistant electrode materials, requires a large space, and has low current per electrode area, which leads to the reduction of efficiency. Proton exchange membrane water electrolysis allows for a compact system design and has a high energy density, but has the disadvantage that platinum-based metals must be essentially used for the electrodes, which increases the cost of hydrogen production. To overcome the drawbacks of the conventional technologies, anion exchange membrane water electrolysis(AEMWE) has been proposed. In the case of the anion exchange membrane electrolysis, there are advantages in that it can use non-platinum metals as electrode materials due to the alkaline environment, and allows for a compact system design, which can provide a satisfactory energy density. However, the anion exchange membrane water electrolysis has not yet been fully studied, and information on the standard exchange membrane or electrode materials is insufficient. Therefore, in order to develop environmentally friendly hydrogen production technologies. active technological development and research on anion exchange membrane electrolysis are required. [DETAILED DESCRIPTION OF THE INVENTION] [Technical Problem] It is an object of the present disclosure to provide an electrode for anion exchange membrane water electrolysis that can achieve improved electrochemical performance and also has excellent durability. It is another object of the present disclosure to provide a method for preparing the electrode. [Technical Solution] According to one aspect of the present disclosure, there is provided an electrode comprising: a metal substrate containing nickel; a first sol-gel coating layer formed on at least one surface of the metal substrate; and a second sol-gel coating layer formed on the first sol-gel layer, wherein the first sol-gel coating layer and the second sol-gel coating layer each independently comprise nickel and iron. According to one embodiment, the metal substrate may comprise a porous metal foam. According to one embodiment, the first sol-gel coating layer and the second sol-gel coating layer may each independently comprise nickel hydroxide and iron hydroxide. According to one embodiment, the first sol-gel coating layer and the second sol-gel coating layer may each independently exist in a state in which nickel hydroxide and iron hydroxide form a three-dimensional gel network structure. According to one embodiment, the first sol-gel coating layer and the second sol-gel coating layer may each independently comprise about 10 to about 25 moles, or about 10 moles or more, or about 15 moles or more, or about 16 moles or more, and about 25 moles or less, or about 20 moles or less, or about 18 moles or less of iron, relative to 100 moles of the nickel. According to one embodiment, the first sol-gel coating layer may have a thickness of about 100 to about 250 nm, or about 100 nm or more, or about 150 nm or more, and about 250 nm or less, or about 200 nm or less. According to one embodiment, the second sol-gel coating layer may have a thickness of about 500 to about 2000 nm, or about 500 nm or more, or about 800 nm or more, and about 2000 nm or less, or about 1000nm or less. According to one embodiment, the thickness of the first sol-gel coating layer: the thickness of the second sol-gel coating layer may be about 1:2 to about 1:10, or 1:5 to about 1:7, or about 1:5 to about 1:6.67. According to one embodiment, the electrode may be used for anion exchange membrane water electrolysis. On the other hand, according to another aspect of the present disclosure, there is provided a method for preparing an electrode, comprising the steps of: preparing a first precursor solution(sol) containing a nickel precursor and an iron precursor; immersing a nickel substrate in the first precursor solution; inducing a sol-gel reaction in the first precursor solution to form a first sol-gel coating layer on the nickel substrate; p