U.S. patent application number 13/389343 was filed with the patent office on 2012-05-31 for capacitive electrode for deionization, and electrolytic cell using same.
This patent application is currently assigned to SION TECH CO., LTD.. Invention is credited to Jae-Hwan Choi, Kyung-Seok Kang.
Application Number | 20120132519 13/389343 |
Document ID | / |
Family ID | 43544777 |
Filed Date | 2012-05-31 |
United States Patent
Application |
20120132519 |
Kind Code |
A1 |
Kang; Kyung-Seok ; et
al. |
May 31, 2012 |
CAPACITIVE ELECTRODE FOR DEIONIZATION, AND ELECTROLYTIC CELL USING
SAME
Abstract
Provided is an electrode using a polymeric solution containing a
cation exchanger or an anion exchanger, and a capacitive
electrolytic cell for deionization using the same.
Inventors: |
Kang; Kyung-Seok; (Daejeon,
KR) ; Choi; Jae-Hwan; (Cheonan-si, KR) |
Assignee: |
SION TECH CO., LTD.
Daejeon
KR
|
Family ID: |
43544777 |
Appl. No.: |
13/389343 |
Filed: |
August 3, 2010 |
PCT Filed: |
August 3, 2010 |
PCT NO: |
PCT/KR10/05091 |
371 Date: |
February 7, 2012 |
Current U.S.
Class: |
204/242 |
Current CPC
Class: |
C02F 1/4691 20130101;
H01M 2300/0082 20130101; H01M 4/56 20130101; H01M 4/50 20130101;
H01M 4/621 20130101; H01M 4/661 20130101; H01M 4/48 20130101; H01M
4/583 20130101; H01M 4/663 20130101; Y02E 60/10 20130101 |
Class at
Publication: |
204/242 |
International
Class: |
C25B 9/00 20060101
C25B009/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 7, 2009 |
KR |
10-2009-0072683 |
Claims
1. A capacitive deionization electrochemical cell, comprising: any
one electrode selected from an anode manufactured by containing a
cation exchange resin therein and a cathode manufactured by
containing an anion exchange resin therein; and a spacer layer
separating the anode from the cathode.
2. The capacitive deionization electrochemical cell of claim 1,
wherein the electrode is manufactured by preparing a slurry
containing a polymer resin having the cation exchanger or a polymer
resin having an anion exchanger and an electrode active material,
and then coating the slurry on a current collector.
3. The capacitive deionization electrochemical cell of claim 2,
wherein the polymer resin having a cation exchanger is a polymer
resin having at least one cation exchanger selected from the group
consisting of a sulfonic acid group (--SO.sub.3H), a carboxyl group
(--COOH), a phosphonic group (--PO.sub.3H.sub.2), a phosphinic
group (--HPO.sub.2H), an arsenic group (--AsO.sub.3H.sub.2), or a
selenonic group (--SeO.sub.3H), and the polymer resin having an
anion exchanger is a polymer resin having at least one anion
exchanger selected from the group consisting of a quaternary
ammonium salt (--NH.sub.3), primary, secondary, or tertiary amine
(--NH.sub.2, --NHR, --NR.sub.2), a quaternary phosphonium group
(--PR.sub.4), or a tertiary sulfonium group (--SR.sub.3).
4. The capacitive deionization electrochemical cell of claim 1,
wherein the electrode active material is at least one active carbon
based material selected from an active carbon powder, an active
carbon fiber, a carbon nanotube, and a carbon aerogel; one or two
or more metal oxide based materials selected from RuO.sub.2,
Ni(OH).sub.2, MnO.sub.2, PbO.sub.2, and TiO.sub.2; and a mixture
thereof.
5. The capacitive deionization electrochemical cell of claim 1,
wherein the current collector is in a sheet, thin film, or plain
weave gold net form, including aluminum, nickel, copper, titanium,
iron, stainless steel, graphite, or a mixture thereof.
6. The capacitive deionization electrochemical cell of claim 1,
wherein the current collector is in an organic resin sheet, thin
film, or plain weave gold net form, selected from an organic
polymer including polyvinylidenefluoride, polystyrene, polyester,
or polyolefine.
7. The capacitive deionization electrochemical cell of claim 1,
wherein the slurry further contains a conductive material.
8. The capacitive deionization electrochemical cell of claim 7,
wherein the conductive material is conductive carbon black.
9. A deionizing apparatus for water treatment, using the
electrochemical cell of claim 1.
10. A metal collecting apparatus for collecting heavy metals or
noble metals in waste water, using the electrochemical cell of
claim 1.
Description
TECHNICAL FIELD
[0001] The present invention relates to a capacitive electrode for
deionization, an electrolytic cell using the same, and a deionizing
apparatus using the same. More particularly, the present invention
relates to an electrode having ion selectivity and enabling
efficient separation and removal of cation and anion.
BACKGROUND ART
[0002] Currently, an ionic material removal method using ion
exchange resin is mainly used as a method for removing an ionic
material in an aqueous solution. This method effectively separate
most ionic materials, but causes a large amount of acidic, basic,
or salty waste liquid to be generated during a procedure of
recycling a resin after completion of ion exchange. Besides,
separation techniques such as a reverse osmosis membrane method, an
electro-dialysis method, and the like are employed, but these
methods have problems such as a decrease in treatment efficiency
due to film fouling, cleansing of the polluted film, periodic
exchange of films, and the like. A capacitive deionization
technique using an electric double layer principle has been studied
in order to solve the problems of the existing deionization
techniques.
[0003] The capacitive deionization technology uses an adsorption
reaction of ions by electric attraction in the electric double
layer formed on a surface of an electrode when electric potential
is applied to the electrode, and thus, the operation occurs at a
low electrode potential (about 1 to 2V), and as a result, energy
consumption is lower as compared with other deionization
technologies. Therefore, the capacitive deionization technology is
valued as a low-energy consumption type next generation
deionization technology.
[0004] However, since deionization capability of the capacitive
deionization technology is still not sufficient, the need to
improve the deionizing capability has emerged. In a case where a
large amount of water is treated and applied to home or industrial
places, the treatment capability by the capacitive deionization
technology never reaches to a necessary level and thus the use of
the capacitive deionization technology is limited.
[0005] Another problem of the capacitive deionization technology is
that ions adsorbed on the electric double layer are not completely
desorbed therefrom, and thus, adsorption efficiency of the ions is
rapidly decreased. According to a CDI process, ion materials are
removed from inflow water by an ion adsorption reaction of electric
double layers formed on a surface of an electrode when 1 to 2 volts
(V) of electrode potential is applied. When the adsorbed ions reach
a capacitive capacitance of the electrode, the adsorbed ions are
desorbed by making the electrode potential to 0 volt (V) or
converting to the contrary potential, thereby recycling the
electrode. Here, the ions having a contrary charge to the ions
adsorbed on the electrode move to the electric double layers due to
a rapid change in electrode potential, and thus, all the adsorbed
ions are not desorbed and remain on the surface of the electrode,
which causes ion adsorption efficiency of the electrode to be
decreased.
TECHNICAL PROBLEM
[0006] An object of the present invention is to provide an
electrode having high adsorption efficiency of ions during the
driving procedure of process while increasing a capacitive
capacitance, an electrolytic cell using the same, and a water
treatment deionizing apparatus using the same.
[0007] Also, an object of the present invention is to solve
problems of decreased ion adsorption efficiency in the desorbing
procedure of the adsorbed ions due to movement of ions having a
contrary polarity to the adsorbed ions to the electrode. In other
words, the object of the present invention is to develop the
techniques for improving ion adsorption efficiency according to the
continuous using or recycling.
[0008] Also, an object of the present invention is to provide a new
electrode capable of exhibiting ion selectivity by using a polymer
having a functional group having ion exchange capacity as a binder
material, an electrolytic cell using the same, and a water
treatment deionizing apparatus manufactured by using the same.
TECHNICAL SOLUTION
[0009] In one general, the present invention is characterized in
that an ion exchangeable polymer resin, that is, a polymer resin
containing a functional group having ion exchange capacity is added
as one constituent component at the time of manufacturing an
electrode, to produce an ion selective electrode capable of
removing or collecting various ions present in water at the time of
water treatment or heavy metals or noble metals at the time of
waste treatment, thereby improving ion adsorption and desorption
efficiency.
[0010] Specifically, the present invention can improve ion
adsorption efficiency and increase an ion adsorption rate. In
addition, according to the present invention, in an electrochemical
cell using the ion selective electrode, an electrode using a
polymer resin having a cation exchange group may be used as an
anode and an electrode using a polymer resin having an anion
exchange group may be used as a cathode. Here, an ion exchange
resin may be added to only one electrode or may be added to both
the cathode and the anode.
[0011] Further, the present invention is characterized in that an
electrode using a cation exchange polymer passes only cations
therethrough and an electrode using an anion exchange polymer
solution passes only anions therethrough can be simply and
economically manufactured. In addition, the present invention is
characterized by providing an electrode having very superior
deionization efficiency, an electrolytic cell using the same, and a
deionizing apparatus using the same.
[0012] More specifically, a method of the present invention
includes:
[0013] (a) dissolving a polymer resin having a cation exchange
group or an anion exchange group in an organic solvent to prepare
an ion selective polymer solution;
[0014] (b) adding an electrode active material to the polymer
solution to prepare a slurry; and
[0015] (c) coating the slurry on a current collector.
[0016] The method may further include (d) removing the organic
solvent from the slurry coated on the current collector to thereby
manufacture a sheet type electrode, after step (c).
[0017] In addition, when a conductive material is further added in
step (d), electric conductivity of the electrode can be further
improved.
[0018] Further, in order to manufacture the electrolytic cell, the
present invention may further include: after manufacturing the
electrode, stacking one electrode and the other electrode and
stacking a spacer layer such as a mesh type polyimide layer or the
like, preventing contact between the electrodes and differentiating
the electrodes as a cathode and an anode.
[0019] Hereinafter, the present invention will be described in more
detail.
[0020] First, in step (a), a polymer resin having a cation exchange
group such as a sulfonic acid group (--SO.sub.3H), a carboxyl group
(--COOH), a phosphonic group (--PO.sub.3H.sub.2), a phosphinic
group (--HPO.sub.2H), an arsenic group (--AsO.sub.3H.sub.2), a
selenonic group (--SeO.sub.3H) may be used, and a polymer resin
having an anion exchanger such as a quaternary ammonium salt
(--NH.sub.3), primary, secondary, or tertiary amine (--NH.sub.2,
--NHR, --NR.sub.2) a quaternary phosphonium group (--PR.sub.4), a
tertiary sulfonium group (--SR.sub.3), or the like, may be used.
This ion exchange polymer resin may be dissolved in the organic
solvent and thereby may be present as a solution type.
Specifically, for example, any one or a mixture of two or more
selected from polystyrene, polysulfone, polyethersulfone,
polyamide, polyester, polyimide, polyether, polyethylene,
polytetrafluoroethylene, or polyglycidylmethacrylate, which have
any one of the above ion exchangers, may be used as the ion
exchange polymer resin, but are not limited thereto. Any resin that
can have a cation exchange group or an anion exchange group may be
used without limitation.
[0021] In addition, the polymer resin may preferably have a weight
average molecular weight of 200,000 to 10,000,000, but is not
limited thereto. The polymer resin having a weight average
molecular weight of the above range is excellent in view of
viscosity of an electrode slurry and property of binding electrode
active materials.
[0022] The organic solvent may be selected according to the kind of
polymer resin. Any one or a mixture of two or more selected from
dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone,
acetone, chloroform, dichloromethane, trichloroethylene, ethanol,
methanol, normal hexane, may be used as the organic solvent
dissolving the above-described polymer resin. However, examples of
the organic solvent are not limited thereto.
[0023] In step (a), the solid content is preferably 10 to 50 wt %
at the time of preparing the polymer solution. If the solid content
is below 10 wt % or above 50 wt %, the polymer solution has either
too high or too low viscosity, and thus, the electrode slurry is
not easily prepared in step (b).
[0024] Next, with reference to step (b), in which the slurry is
prepared by adding an electrode active material, a conductive
material, or a mixture thereof to the polymer solution, addition of
the electrode active material can improve the specific surface area
of the electrode and the capacitive capacitance. Also, addition of
the conductive material can improve electric conductivity of the
electrode.
[0025] The electrode active material may be an active carbon based
material having a high specific surface area, and for example, an
active carbon powder, an active carbon fiber, a carbon nanotube, a
carbon aerogel, or a mixture thereof may be used as the electrode
active material. The electrode active material is preferably
prepared and used in a powder type. Alternatively, the electrode
active material may be a metal oxide based material, and for
example, RuO.sub.2, Ni(OH).sub.2, MnO.sub.2, PbO.sub.2, TiO.sub.2,
or a mixture thereof may be used as the electrode active material
or may be added to the electrode active material. The content range
of this electrode active material may be controlled depending on
necessary physical properties thereof. More specifically, without
being limited to, an electrode active material having an average
particle size of 10 .mu.m or less, or specifically 10 nm to 10
.mu.m is preferably used so as to increase the specific surface
area of the electrode and the capacitive capacitance. In addition,
the electrode active material is preferably used in a range of 600
to 900 parts by weight based on 100 parts by weight of the polymer
material having an ion exchange functional group, so as to
manufacture an electrode exhibiting ion selectivity and having high
capacitive capacitance.
[0026] In addition, according to the present invention, as
necessary, the conductive material may be additively used together
with the electrode active material, and any conductive material
that can have a low electric resistance may be used without
limitation. Specifically, for example, conductive carbon black,
such as acetylene black, ketchen black, XCF carbon, SRF carbon, or
the like may be used.
[0027] The content range of this conductive material may be
controlled depending on necessary physical properties thereof. More
specifically, without being limited to, a conductive material
having an average particle size of 2 .mu.m or less, preferably 1
.mu.m or less, or more preferably 10 nm to 1 .mu.m is used so as to
increase electric conductivity of the electrode. In addition, the
conductive material is not significantly limited in the use amount
thereof, but the conductive material is preferably used in a range
of 1 to 20 parts by weight based on 100 parts by weight of the
electrode active material so as to increase electric conductivity
of the electrode and the capacitive capacitance.
[0028] Next, with reference to step (c) in which the slurry is
coated on the current collector, a material having excellent
conductivity so that an electric field can be uniformly distributed
on a surface of the manufactured electrode when current is supplied
to the electrode through a power supply device can be preferably
used as the current collector. The current collector may be used in
a sheet, thin film, or plain weave gold net form, which includes,
for example, aluminum, nickel, copper, titanium, iron, stainless
steel, graphite, or a mixture thereof. In addition, an organic
resin sheet, thin film, or film, which includes
polyvinylidenefluoride, polystyrene, polyester, polysulfone,
polyolefine, or the like, may be used.
[0029] In addition, the coating method may be performed by spray,
dip coating, knife casting, doctor blade, spin coating, or the
like, without limitation thereto. The coating thickness is
preferably in a range of 50 to 300 .mu.m so as to decrease electric
resistance of the electrode and improve deionization
efficiency.
[0030] In addition, step (c) is repeatedly performed as necessary,
and thus an electrode having a particular thickness can be
manufactured.
[0031] Next, in step (d), the organic solvent in the slurry coated
on the current collector is removed, and thereby a sheet type
porous carbon electrode can be manufactured. The method for
removing the organic solvent may include a method of separating the
organic solvent by performing drying under normal pressure or
vacuum at a temperature atmosphere of several tens or several
hundreds of degrees centigrade, or using a nonsolvent.
Specifically, the organic solvent may be removed by performing
drying under normal pressure or vacuum at a temperature atmosphere
of room temperature to 200.degree. C. Alternatively, the current
collector coated with the slurry is dipped in a nonsolvent of any
one or more selected from distilled water, alcohol,
dimethylformamide, dimethylacetamide, N-methyl-2-pyrrolidone, and
acetone for 1 to 24 hours, thereby eluting and removing the organic
solvent while occurring phase-change (solidification) of the
polymer resin.
[0032] An electrochemical cell using the ion selective electrode
manufactured by the manufacturing method of the present invention
as only one electrode selected from a cathode and an anode or both
the cathode and the anode is also included in the scope of the
present invention. The electrochemical cell forms electrodes by
application of electricity, and this means a form consisting of a
cathode, an anode, and a spacer. This electrochemical cell includes
capacitive type deionization cell, capacitor, and the like. The
electrochemical cell includes also those in which cathodes and
anodes are alternately stacked in two or more layers. Since the
number of stacked cathodes and anodes has a relation with the
capacitance, the cathodes and the anodes are properly stacked as
necessary.
[0033] In other words, in cases where an electrochemical cell is
manufactured by employing the electrode according to the present
invention, the ion selective electrode is used as only one
electrode selected from a cathode and an anode and an electrode
manufactured by using a polymer binder not having an ion exchange
group is used as the other electrode. Even in this case, excellent
adsorption and desorption of ions can be achieved.
[0034] More preferably, the ion selective electrode is employed as
both the anode and the cathode, thereby increasing the capacitive
capacitance and facilitating adsorption and desorption of ions
during a driving procedure of the process.
[0035] According to the present invention, in the electrochemical
cell using the ion selective electrode, the electrode using a
polymer resin having a cation exchanger may be used as an anode and
the electrode using a polymer resin having an anion exchanger may
be used as a cathode.
ADVANTAGEOUS EFFECTS
[0036] According to the ion exchangeable electrode of the present
invention, the polymer solution having an ion exchange group is
used as a binder, thereby facilitating adsorption and desorption of
ions, increasing the ion adsorption and desorption rate, and
improving ion adsorption efficiency. Further, the distance between
electrodes can be minimized, and thus, ionic materials can be
effectively and quickly adsorbed.
[0037] Further, according to the present invention, since the
electrode is manufactured by using polymer binder having an ion
exchange group, a separate binder does not need to be used and the
manufacturing costs are decreased, and thus, the electrode of the
present invention can be easily used as a capacitive type
deionization electrode, and the application range of this
technology can be extended from a large-scale treatment of
industrial water to a small-scale treatment of home purification
water.
DESCRIPTION OF DRAWINGS
[0038] The above and other objects, features and advantages of the
present invention will become apparent from the following
description of preferred embodiments given in conjunction with the
accompanying drawings, in which:
[0039] FIG. 1 is a graph showing deionization efficiency according
to Examples 1 and 2 of the present invention and Comparative
Example 1; and
[0040] FIG. 2 is a graph showing deionization efficiency of
Examples 1 and 3 of the present invention.
BEST MODE
[0041] Hereinafter, the present invention will be described by the
examples in detail, but the present invention is not limited to the
following examples.
Preparative Example 1
[0042] Preparation of Slurry Having Cation Exchange Group
[0043] 1.0 g of sodium sulfonated polystyrene (cation exchange
capacity=3 meq/g) having a cation exchanger, which was produced
through a sulfonation reaction, was mixed with 20 g of
dimethylacetamide (DMAc), to prepare a polymer solution, and then
6.0 g of an activated carbon powder (specific surface area=1600
m.sup.2/g) was mixed into the polymer solution, thereby preparing a
cation exchange electrode slurry.
Preparative Example 2
[0044] Preparation of Slurry Having Anion Exchange Group
[0045] 1.0 g of polystyrene (anion exchange capacity=3 meq/g)
having an ammonium chloride anion exchanger, which was produced
through an amination reaction, was mixed with 20 g of
dimethylacetamide, to prepare a polymer solution, and then 6.0 g of
an activated carbon powder (specific surface area=1600 m.sup.2/g)
was mixed into the polymer solution, thereby preparing an anion
exchange electrode slurry.
Preparative Example 3
[0046] Preparation of Polyvinylidenefluoride Slurry
[0047] 1.0 g of polyvinylidenefluoride (PVdF, Mw=275,000) was mixed
with 20 g of dimethyl acetaldehyde, to prepare a polymer solution,
and then 8.0 g of an activated carbon powder (specific surface
area=1600 m.sup.2/g) was mixed into the polymer solution, thereby
preparing an electrode slurry
Preparative Example 4
[0048] Preparation of Slurry Having Cation Exchange Group and
Conductive Material Added Thereto
[0049] 1.0 g of sodium sulfonated polystyrene (cation exchange
capacity=3 meq/g) having a cation exchanger, which was produced
through a sulfonation reaction, was mixed with 20 g of dimethyl
acetaldehyde (DMAc), to prepare a polymer solution, and then 6.0 g
of an activated carbon powder (specific surface area=1600
m.sup.2/g) and 0.5 g of carbon black (average diameter=19 nm) were
mixed to the polymer solution, thereby preparing a cation exchange
electrode slurry.
Preparative Example 5
[0050] Preparation of Slurry Having Anion Exchange Group and
Conductive Material Added Thereto
[0051] 1.0 g of chloro-ammoniated polystyrene (anion exchange
capacity=3 meq/g) having an anion exchanger, which was produced
through an amination reaction, was mixed with 20 g of dimethyl
acetaldehyde, to prepare a polymer solution, and then 6.0 g of an
activated carbon powder (specific surface area=1600 m.sup.2/g) and
0.5 g of carbon black (average diameter=19 nm) were mixed to the
polymer solution, thereby preparing a cation exchange electrode
slurry.
Example 1
[0052] In order to find ion adsorption performance of electrodes
when both a cathode and an anode are manufactured by a binder
having an ion exchanger, the electrodes were manufactured such that
the anode and the cathode each have an ion exchanger.
[0053] Electrode Manufacturing
[0054] The slurry prepared from Preparative Example 1 and the
slurry prepared from Preparation Example 2 were respectively coated
on conductive graphite sheets (thickness: 250 .mu.m) by a doctor
blade such that one surface thereof had a coating thickness of 150
.mu.m, followed by drying at room temperature, thereby
manufacturing an anode having a cation exchanger and a cathode
having an anion exchanger, respectively.
Example 2
[0055] In order to check ion adsorption performance of electrodes
when only one electrode is manufactured by a binder having an
ion-exchange group, the electrodes were manufactured such that only
an anode has an ion-exchange group.
[0056] Electrode Manufacturing
[0057] The slurry prepared from Preparative Example 1 and the
slurry prepared from Preparation Example 3 were respectively coated
on conductive graphite sheets (thickness: 250 .mu.m) by a doctor
blade such that one surface thereof had a coating thickness of 150
.mu.m, followed by drying at room temperature, thereby
manufacturing an anode having a cation exchanger and a cathode made
of PVdF but not having an ion-exchange group.
Example 3
[0058] In order to check ion adsorption performance of electrodes
when the electrodes are manufactured by adding a conductive
material thereto, the electrodes having the conductive material
added thereto were manufactured.
[0059] Electrode Manufacturing
[0060] The slurry prepared from Preparation Example 4 and the
slurry prepared from Preparation Example 5 were respectively coated
on conductive graphite sheets (thickness: 250 .mu.m) by a doctor
blade such that one surface thereof had a coating thickness of 150
.mu.m, followed by drying at room temperature, thereby
manufacturing an anode having a cation exchanger and a cathode
having an anion exchanger, respectively.
Comparative Example 1
[0061] It was tried to check ion adsorption performance of
electrodes manufactured by a binder not having an ion-exchange
group.
[0062] Electrode Manufacturing
[0063] The slurry prepared from Preparation Example 3 was
respectively coated on conductive graphite sheets (thickness: 250
.mu.m) by a doctor blade such that one surface thereof had a
coating thickness of 150 .mu.m, followed by drying at room
temperature, thereby manufacturing a cathode and an anode,
respectively.
Experimental Example 1
[0064] Each deionization cell was manufactured by using each of the
electrodes manufactured from examples 1, 2, and 3 and the
comparative example 1.
[0065] After the manufactured electrodes were cut into 10.times.10
cm.sup.2, a 100 .mu.m thickness spacer (200 mesh, polyimide) was
installed between the cathode and the anode such that contact
between the two electrodes was prevented and fluid passed through
the spacer. Each of the electrodes was pierced to form a hole of 1
cm at the center thereof so that a solution flowed out from four
surfaces to the center of the electrode via the spacer. An acryl
plate of 15.times.15 cm.sup.2 cm size was fixed to the outsides of
the cathode and the anode by using bolts, thereby manufacturing a
capacitive deionization single cell.
[0066] A NaCl solution of 250 mg/L was supplied at a rate of 20
mL/min while an electrode potential of 1.4V was uniformly applied.
Deionization efficiency was analyzed by measuring electric
conductivity of outflow water. Cell driving was carried out in a
manner that the electrode potential was changed to 0.0V to perform
ion desorption for 2 minutes after ion adsorption for 3 minutes was
performed. Deionization experiment results for three kinds of cells
were shown in FIG. 1.
[0067] As shown in FIG. 1, Example 1, in which both the cathode and
the anode both were manufactured by using a polymer resin having an
ion exchanger, exhibited the most excellent ion adsorption
performance. Also, Example 2, in which only the anode was
manufactured by using a polymer resin having an ion exchanger,
exhibited a high ion adsorption performance as compared with the
comparative example. Therefore, it can be seen that the present
invention can be selectively employed in the cathode or the anode,
and preferably employed in both the cathode and the anode.
Experimental Example 2
[0068] It was tried to check a difference in ion adsorption
performance according to the presence or absence of a conductive
material. An ion adsorption experiment was performed on the
electrodes manufactured from Examples 1 and 3 in the same manner
and under the same conditions as Experimental Example 1.
[0069] As shown in FIG. 2, it can be seen that ion adsorption
performance can be further improved when the conductive material is
added.
* * * * *