Technical Field
[0002] 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
15 layer while exhibiting excellent performance, and a method for
manufacturing the electrode.
BACKGROUND ART
[0003] A technology of producing hydroxides, hydrogen, and
chlorine by electrolyzing low-cost brine such as seawater is
20 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.
[0004] As a method for electrolyzing brine, an ion exchange
25 membrane method is currently most widely used, in which an ion
2
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.
5 [0005] Meanwhile, the electrolysis process of brine is
achieved through a reaction as shown in the following
electrochemical reaction equation.
[0006] Reaction in anode: 2Cl- → Cl2 + 2e- (E0 = +1.36 V)
[0007] Reaction in cathode: 2H2O + 2e- → 2OH- + H2 (E0 = -0.83
10 V)
[0008] Entire reaction: 2Cl- + 2H2O → 2OH- + Cl2 + H2 (E0 = -
2.19 V)
[0009] Between the two electrodes in which the electrolysis
15 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
20 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
25 metal.

CLAIMS
1. An electrode for electrolysis comprising:
a metal substrate layer; and
5 a first coating layer to an N-th coating layer, wherein
the first coating layer is formed at least one surface of the
metal substrate layer, and the first coating layer to the Nth coating layer are formed sequentially stacked, and Equations
1 and 2 below are satisfied:
10 [Equation 1]
CSn-1 < CSn
[Equation 2]
CTn-1 > CTn
wherein in the Equations,
15 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.
20 2. The electrode of claim 1, wherein Equation 3 below is
further satisfied:
[Equation 3]
CSn-1 + CTn-1 = CSn + CTn
wherein in the Equations,
25 n is an integer of 2 to N, and
36
N is an integer of 2 or greater.
3. The electrode of claim 1, wherein Equation 1 above is
Equation 1-2 below:
5 [Equation 1-2]
1 < CSn / CSn-1 ≤ 2.
4. The electrode of claim 1, wherein Equation 2 above is
Equation 2-2 below:
10 [Equation 2-2]
0.5 ≤ CTn / CTn-1 < 1.
5. The electrode of claim 1, wherein CS1 + CT1 is 30 mol% to
60 mol%.
15
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.
20
7. The electrode of claim 6, wherein the content of a
platinum group metal in the first coating layer to the N-th
coating layer is constant.
25 8. The electrode of claim 6, wherein the first coating layer
37
to the N-th coating layer comprise ruthenium, iridium, and
platinum.
9. The electrode of claim 8, wherein the total content of
5 ruthenium in the first coating layer to the N-th coating layer
is 20 g/m2 or greater.
10. The electrode of claim 1, wherein the N is an integer of
4 to 10.
10
11. The electrode of claim 1, wherein the metal substrate
layer comprises one or more selected from the group consisting
of nickel, titanium, tantalum, aluminum, hafnium, zirconium,
molybdenum, tungsten, and stainless steel.