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US-12624469-B2 - Electrode for electrolysis

US12624469B2US 12624469 B2US12624469 B2US 12624469B2US-12624469-B2

Abstract

An electrode for electrolysis and a method for manufacturing the same, wherein an electrode coating layer for electrolysis is provided in plurality, and the tin content in each coating layer is configured to increase as the distance from a substrate increases, and the titanium content therein is configured to decrease as the distance from the substrate increases, so that excellent performance is maintained, and also delamination and the like does not occur during firing, so that excellent durability may be implemented.

Inventors

  • Yoon Bin Park
  • In Sung Hwang
  • Hun Min PARK
  • Dong Chul Lee

Assignees

  • LG CHEM, LTD.

Dates

Publication Date
20260512
Application Date
20211108
Priority Date
20201112

Claims (15)

  1. 1 . An electrode for electrolysis comprising: a metal substrate layer; and a first coating layer to an N-th coating layer, wherein the first coating layer is formed on at least one surface of the metal substrate layer, and the first coating layer to the N-th coating layer are formed sequentially stacked, and Equations 1 and 2 below are satisfied: CS n-1 <CS n [Equation 1] CT n-1 <CT n [Equation 2] wherein in the Equations, CS n is a Sn content (mol %) in an n-th coating layer, CT n is a Ti content (mol %) in an n-th coating layer, n is an integer of 2 to N, and N is an integer of 4 or greater.
  2. 2 . The electrode of claim 1 , wherein Equation 3 below is further satisfied: CS n-1 +CT n-1 =CS n +CT n [Equation 3] wherein in the Equations, n is an integer of 2 to N, and N is an integer of 4 or greater.
  3. 3 . The electrode of claim 1 , wherein the Equation 1 above is Equation 1-2 below: 1<CS n /CS n-1 ≤2. [Equation 1-2]
  4. 4 . The electrode of claim 1 , wherein the Equation 2 above is Equation 2-2 below: 0.5≤CT n /CT n-1 <1. [Equation 2-2]
  5. 5 . The electrode of claim 1 , wherein CS 1 +CT 1 is 30 mol % to 60 mol %.
  6. 6 . The electrode of claim 1 , wherein the first coating layer to the N-th coating layer comprise one or more platinum group metals selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum.
  7. 7 . The electrode of claim 6 , wherein a content of the platinum group metal in the first coating layer to the N-th coating layer is constant.
  8. 8 . The electrode of claim 6 , wherein the first coating layer to the N-th coating layer comprise ruthenium, iridium, and platinum.
  9. 9 . The electrode of claim 8 , wherein a total content of the ruthenium in the first coating layer to the N-th coating layer is 20 g/m 2 or greater.
  10. 10 . The electrode of claim 1 , wherein the N is an integer of 4 to 10.
  11. 11 . The electrode of claim 1 , wherein the metal substrate layer comprises one or more of nickel, titanium, tantalum, aluminum, hafnium, zirconium, molybdenum, tungsten, or stainless steel.
  12. 12 . A method for manufacturing an electrode for electrolysis, the method comprising: applying and firing a first coating composition on at least one surface of a metal substrate to form a first coating layer; and sequentially applying and firing a second coating composition to an N-th coating composition on the formed first coating layer to form a second coating layer to an N-th coating layer, wherein Equations 4 and 5 below are satisfied: CS′ n-1 <CS′ n [Equation 4] CT′ n-1 >CT′ n [Equation 5] wherein in the Equations, CS′ n is a Sn content (mol %) in an n-th coating composition, CT′ n is a Ti content (mol %) in an n-th coating composition, n is an integer of 2 to N, and N is an integer of 4 or greater.
  13. 13 . The method of claim 12 , wherein the first coating composition to the N-th coating composition comprise one or more platinum group metals selected from the group consisting of ruthenium, rhodium, palladium, osmium, iridium, and platinum.
  14. 14 . The method of claim 12 , wherein the firing is performed for 1 hour or less at a temperature of 400° C. to 600° C.
  15. 15 . The method of claim 12 , wherein a solvent of the first coating composition to the N-th coating composition comprises one or more g of butanol, isopropyl alcohol, or butoxyethanol.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a national phase entry under 35 U.S.C. § 371 of International Application No. PCT/KR2021/016154, filed on Nov. 8, 2021, which claims the benefit of Korean Patent Application No. 10-2020-0151310, filed on Nov. 12, 2020, the disclosures of which are incorporated herein in their entirety by reference. TECHNICAL FIELD The present invention relates to an electrode for electrolysis capable of suppressing delamination of a coating layer thanks to excellent physical stability of the coating layer while exhibiting excellent performance, and a method for manufacturing the electrode. BACKGROUND ART A technology of producing hydroxides, hydrogen, and chlorine by electrolyzing low-cost brine such as seawater is widely known. Such an electrolysis process is also commonly referred to as a chlor-alkali process, the performance and reliability of which have been proven through decades of commercial operation. As a method for electrolyzing brine, an ion exchange membrane method is currently most widely used, in which an ion exchange membrane is installed inside an electrolyzer to divide the electrolyzer into a cation chamber and an anion chamber, and brine is used as an electrolyte to obtain chlorine gas from an anode and hydrogen and caustic soda from a cathode. Meanwhile, the electrolysis process of brine is achieved through a reaction as shown in the following electrochemical reaction equation. 2Cl−→Cl2+2e− (E0=+1.36 V)  Reaction in anode 2H2O+2e−→2OH−+H2 (E0=−0.83 V)  Reaction in cathode 2Cl−+2H2O→2OH−+Cl2+H2 (E0=−2.19 V)  Entire reaction Between the two electrodes in which the electrolysis of brine is performed, as the anode, a precious metal-based electrode referred to as a dimensionally stable anode (DSA) has been developed and used, and particularly, various anodes capable of operating an electrolysis process even with a low voltage are being developed by employing a platinum group metal such as ruthenium, iridium, palladium, and platinum as a coating layer component. In addition, research is being actively conducted to improve various properties of an anode, such as current efficiency, by additionally including various components in a coating layer, other than a platinum group metal. As an example of the research, it is known that when a tin component is included in a coating layer in addition to a platinum group metal, it is possible to increase anode performance, and improve current efficiency and selectivity. However, the tin component has a low thermal expansion coefficient compared to other metal elements, and thus, may cause cracking and delamination in the coating layer during a high-temperature firing process. Therefore, if it is possible to suppress the above-described limitation of a tin component while including a platinum group metal and a tin component together in a coating layer, it is possible to provide an anode for electrolysis excellent in terms of durability and performance. DISCLOSURE OF THE INVENTION Technical Problem The present disclosure provides an electrode for electrolysis which exhibits excellent performance, but does not exhibit durability deterioration such as cracking or delamination by allowing a tin component together with a platinum group metal to be included in a coating layer, while properly controlling the distribution of the tin component in the coating layer. Technical Solution According to an aspect of the present technology, there are provided an electrode for electrolysis and a method for manufacturing the electrode for electrolysis. (1) The present technology provides an electrode for electrolysis including a metal substrate layer, and a first coating layer to an N-th coating layer, wherein the first coating layer is formed on at least one surface of the metal substrate layer, and the first coating layer to the N-th coating layer are formed sequentially stacked, and Equations 1 and 2 below are satisfied: CSn-1<CSn  [Equation 1] CTn-1<CTn  [Equation 2] In the Equations, CSn is the Sn content (mol %) in an n-th coating layer, CTn is the Ti content (mol %) in an n-th coating layer, n is an integer of 2 to N, and N is an integer of 2 or greater. (2) In (1) above, the present technology provides an electrode for electrolysis characterized in that Equation 3 is further satisfied: CSn-1+CTn-1=CSn+CTn  [Equation 3] In the Equations, n is an integer of 2 to N, and N is an integer of 2 or greater. (3) In (1) or (2) above, the present technology provides an electrode for electrolysis characterized in that Equation 1 is Equation 1-2 below: 1<CSn/CSn-1≤2  [Equation 1-2] (4) In any one of (1) to (3) above, the present technology provides an electrode for electrolysis characterized in that Equation 2 above is Equation 2-2 below: 0.5≤CTn/CTn-1<1  [Equation 2-2] (5) In any one of (1) to (4) above, the present technology provides an electrode for electrolysis characterized in that CS1+CT1 is 30 mol % to 60 mol %.(6) I