KR20110080393A - Method of preparing electrode for capacitive deionization device, electrode for capacitive deionization device, and capacitive deionization device having the electrode - Google Patents

Abstract

PURPOSE: An electrical suction/deionizing device, an electrode for the device and a method of manufacturing the electrode are provided to improve a hydrophilic property since an electrode containing a hydrophobic active-material is electrochemically oxidized. CONSTITUTION: A method of manufacturing an electrode for an electrical suction/deionizing device comprises next steps. An electrode containing a hydrophobic material is electrochemically oxidized in a reaction chamber(11). The electrode further contains binder and a conductive material(12). The electrode is manufactured by a powder type of a hydrophobic active-material.

Description

Method of preparing electrode for capacitive deionization device, electrode for capacitive deionization device, and capacitive deionization device having electrode the electrode}

Disclosed are a method for producing an electrode for an electrosorption deionization apparatus, an electrode for an electrosorption deionization apparatus, and an electrosorption deionization apparatus comprising the electrode. More specifically, a method for producing an electrode for an electroadsorption deionization apparatus comprising electrochemically oxidizing an electrode containing a hydrophobic active material, an electrode for an electrosorption deionization apparatus and an electrosorption deionization apparatus comprising the electrode Is disclosed.

Tap water supplied to households contains hardness components, although the content varies by region. In particular, tap water has a very high hardness in Europe, where limestone is introduced into groundwater.

There is a problem in that energy efficiency is greatly reduced because scale is easily formed on the inner wall of a heat exchanger or a boiler tube in a home appliance using water having a high concentration of hardness component (ie, hard water). Hard water is also unsuitable for washing water. In order to remedy this problem, (i) a method of removing scales generated using chemicals, and (ii) soft water is prepared using ion exchange resins, and then contaminated ion exchange resins in large quantities of high concentration brine. And chemical methods to regenerate. However, these methods have problems such as low user convenience and causing environmental pollution, and thus a technology for softening hard water in a simple and environmentally friendly manner is required.

CDI (Capacitive Deionization) is a technique of adsorbing and removing ionic substances in a medium by applying voltage to a carbon electrode having nano-sized pores and making them polar. In addition, the technique applies a reverse voltage to the electrode for electrode regeneration to desorb the adsorbed ionic material and to discharge it with water. CDI does not require chemicals for regeneration and has the advantage of eliminating the need for ion exchange resins and expensive filters or membranes. In addition, the hardness components such as Cl and Ca ^{2 +,} Mg ^{2 + -} has the advantage of improving the power storage capacity without discharging harmful ion, such as.

In CDI, when a medium containing dissolved ions (i.e., an electrolyte) flows between carbon electrodes, when a direct voltage of low potential difference is applied, the anion component is dissolved in the anode and the cation component is concentrated on the cathode. When the application is stopped, the adsorbed ions are desorbed from the electrode.

Here, the carbon electrode has to meet the requirements of low electrode resistance and wide specific surface area, and thus, the carbon electrode is manufactured by binding activated carbon with polytetrafluoroethylene (PTFE), or a resorcinol formaldehyde resin is used. After carbonization, a plate-shaped carbon electrode may be manufactured through a complicated drying process.

As an electrode for commercial CDI, an electrode produced by binding activated carbon with PTFE to form a sheet is mainly used. Activated carbon has a large specific surface area and developed pores, and thus has the advantage of high processing capacity when used as an active material in an electrode for CDI.

In addition, although high surface area graphite (HSAG) has a high graphitization degree, its specific surface area is relatively high and inexpensive, and thus it is expected to be applied to a new active material.

However, the electrode containing the carbon material as described above has a problem in that the wettability of the electrode against influent is low when applied to CDI due to its poor hydrophilicity. This drop in wettability occurs because the hydrophobic carbon material and the hydrophilic inflow water repel each other, which causes a decrease in the capacitance and deionization rate of the electrode.

One embodiment of the present invention provides a method for producing an electrode for an electroadsorption deionization device comprising the step of electrochemically oxidizing an electrode comprising a hydrophobic active material.

Another embodiment of the present invention provides an electrode for an electroadsorption deionization device comprising an electrochemically oxidized active material.

Another embodiment of the present invention provides an electroadsorption deionization device having the electrode.

One aspect of the invention,

It provides a method for producing an electrode for an electroadsorption deionization device comprising the step of electrochemically oxidizing an electrode comprising a hydrophobic active material.

The electrode may further include a binder and a conductive agent.

The electrode may be prepared using a hydrophobic active material in powder form.

The hydrophobic active material may include a carbon material.

The carbon material may include at least one selected from the group consisting of activated carbon, carbon nanotubes (CNT), mesoporous carbon, activated carbon fibers, graphite, and graphite oxide.

The graphite may include high surface area graphite (HSAG).

The electrochemical oxidation of the electrode is performed in an electrochemical cell comprising the electrode, the counter electrode, the electrolyte in which these electrodes are submerged, and a separator that electrically insulates the electrode from the counter electrode, wherein the electrode is The cathode may act as a cathode and the counter electrode may act as a cathode.

The electrode and the corresponding electrode may be the same or different from each other.

The electrolyte may be an acidic, alkaline or neutral solution.

In the electrochemical oxidation of the electrode, the amount of charge charged in the electrochemical cell may be 20 ~ 30,000C / g.

By the electrochemical oxidation of the electrode, the contact angle of the electrode and the hydrophilic electrolyte can be reduced.

The manufacturing method of the electrode for the electrosorption deionization device may further comprise the step of washing the electrochemically oxidized electrode with a cleaning liquid.

Another aspect of the invention,

Provided is an electrode for an electroadsorption deionization device comprising an electrochemically oxidized active material.

The electrode for the electroadsorption deionization device may comprise an acidic functional group.

The content of the acidic functional group per unit weight of the electrode may be 0.7 ~ 5mmol / g.

The acidic functional group may include at least one selected from the group consisting of a carboxyl group (COOH), a lactone group (COO) and a phenol group.

Another aspect of the invention,

Provided is an electroadsorption deionizer having the electrode.

According to one embodiment of the present invention, by including the step of electrochemically oxidizing the electrode containing a hydrophobic active material, there can be provided a method of manufacturing an electrode for an electrosorption deionization device with improved hydrophilicity.

According to another embodiment of the present invention, an electrode for an electroadsorption deionization device having improved wettability to a hydrophilic electrolyte (eg, hard water) may be provided by including an electrochemically oxidized active material.

According to another embodiment of the present invention, an electroadsorption deionization apparatus having improved electrode capacitance, deionization rate, regeneration rate of the electrode, and lifetime of the device may be provided by including the electrode.

1 is a cross-sectional view schematically showing an electrochemical cell used in the method for manufacturing an electrode for an electroadsorption deionization apparatus according to an embodiment of the present invention.
2 is a cross-sectional view schematically showing an embodiment of an electroadsorption deionization apparatus having an electrode according to an embodiment of the present invention.
3A and 3B are photographs showing the electrochemically oxidized electrode and the hard water contacting each other prepared according to an embodiment of the present invention, and FIG. This is a picture taken in contact.
4 is a diagram illustrating a method of obtaining a charge amount and a discharge amount by showing a change in ion conductivity of effluent water according to a treatment time when treating influent water using a conventional electroadsorption deionizer.
Figures 5a and 5b is the electrode according to the prior art to change the ion conductivity of the effluent according to the treatment time when the deionization of the influent using an electroadsorption deionizer comprising an electrode according to an embodiment of the present invention, respectively It is a graph compared with the electroadsorption deionization apparatus including a.
6A and 6B illustrate an electrode according to the prior art for changing the amount of charge according to the number of charge cycles when deionization of influent water is performed using an electroadsorption deionization apparatus including an electrode according to an embodiment of the present invention. It is the graph shown compared with the electrosorbing deionizer containing.
7A and 7B illustrate the electrode according to the prior art for changing the discharge rate with time when deionization of influent water is performed using an electroadsorption deionization apparatus including an electrode according to an embodiment of the present invention, respectively. It is a graph shown in comparison with the electrosorption deionization apparatus.

Next, a method of manufacturing an electrode for an electroadsorption deionization apparatus according to an embodiment of the present invention, an electrode manufactured by the method, and an electrosorption deionization apparatus including the electrode will be described in detail with reference to the accompanying drawings. .

Method for producing an electrode for an electroadsorption deionization device according to an embodiment of the present invention includes the step of electrochemically oxidizing the electrode comprising a hydrophobic active material. By electrochemically oxidizing the electrode, the hydrophobic active material included in the electrode decreases hydrophobicity and increases hydrophilicity, which will be described later.

The hydrophobic active material may include a carbon material. The carbon material may include at least one selected from the group consisting of activated carbon, carbon nanotubes (CNT), mesoporous carbon, activated carbon fibers, graphite, and graphite oxide. In addition, the graphite may include high surface area graphite (HSAG). In the present specification, 'high surface area graphite' means graphite having a specific surface area of 30 m ² / g or more.

In addition, the electrode may further include a binder and a conductive agent. In this case, the electrode may be manufactured using a hydrophobic active material in powder form. For example, the electrode may be prepared by putting a hydrophobic active material and a conductive agent in a powder form into a binder suspension, stirring the paste, and then kneading the stirred mixture.

The binder may include styrene butadiene rubber (SBR), carboxymethyl cellulose (CMC), polytetrafluoroethylene (PTFE), and the like.

The conductive agent may include carbon black, VGCF (Vapor Growth Carbon Fiber), graphite, and a mixture of two or more thereof.

Hereinafter, the step of electrochemically oxidizing the electrode will be described in detail with reference to FIG. 1.

FIG. 1 is a schematic cross-sectional view of an electrochemical cell 10 used in a method of manufacturing an electrode 13a for an electroadsorption deionization apparatus according to an embodiment of the present invention.

Referring to FIG. 1, the electrochemical cell 10 includes a reaction vessel 11, an electrolyte solution 12, an electrode 13a and a corresponding electrode 13b immersed in the electrolyte solution 12, and the electrode 13a. The separator 14 may be electrically insulated from the corresponding electrode 13b.

In the electrochemical cell 10, the electrode 13a may act as a cathode and the corresponding electrode 13b may act as a cathode. That is, in the electrochemical cell 10, when a positive potential is applied to the electrode 13a and a negative potential is applied to the electrode 13b, the electrode 13a as an anode is oxidized electrochemically. Here, whether the electrode 13a is electrochemically oxidized may be determined by washing the electrode 13a with a washing solution such as deionized water under stirring and then titrating the washing solution with an alkaline solution, and / or with the electrode 13a. This can be confirmed by measuring the contact angle of the hydrophilic electrolyte (ex. Hard water). That is, when the hydrophobic active material contained in the electrode 13a is electrochemically oxidized, an acidic functional group containing oxygen is present on the surface of the active material and the titration of the acidic functional group is performed by titrating the cleaning solution of the electrode 13a with an alkaline solution. The amount can be measured, and the contact angle between the electrode 13a and the hydrophilic electrolyte becomes smaller than before the electrode 13a is electrochemically oxidized. In the present specification, the 'contact angle' means an angle at which the free surface of the liquid forms a solid plane when the liquid (ie, a hydrophilic electrolyte such as hard water) is in contact with the solid (ie, the electrode). This contact angle is determined by the cohesion between the liquid molecules and the adhesion between the liquid and solid surfaces. In this way, when the amount of acidic functional groups formed on the surface of the electrode 13a increases, the contact angle between the electrode 13a and the hydrophilic electrolyte decreases, the hydrophilicity of the surface of the electrode 13a is improved, and the hydrophilic electrolyte (ex. The wettability of the electrode 13a with respect to is increased. In addition, it is known that the specific surface area of the electrode 13a is proportional to the amount of the acidic functional group present on the surface of the electrode 13a, that is, the amount of the alkaline solution used for titration of the acidic functional group (Carbon 37 (1999), 85 -96, CUPittman et al).

As described above, the content of the acidic functional group per unit weight of the electrochemically oxidized electrode may be 0.7 to 5 mmol / g. When the content of the acidic functional group is within the above range, wettability may be improved.

The acidic functional group may include at least one oxygen-containing functional group selected from the group consisting of a carboxyl group (COOH), a lactone group (COO) and a phenol group.

The electrode 13a and the corresponding electrode 13b may be the same or different from each other. As an example, the electrode 13a and the corresponding electrode 13b may each include activated carbon. As another example, the electrode 13a may include high surface area graphite, and the corresponding electrode 13b may include activated carbon.

The electrolyte solution may be an acidic solution such as H ₂ SO ₄ aqueous solution, an alkaline solution such as KOH aqueous solution, or a neutral solution such as KCl aqueous solution.

In addition, in the electrochemical oxidation of the electrode, the amount of charge charged in the electrochemical cell may be 20 ~ 30,000C / g. If the charged charge amount is within the above range, the hydrophilicity improving effect can be obtained in a short time at low energy cost.

After the electrochemically oxidized electrode 13a as described above is washed with a washing solution such as distilled water, the positive electrode (101a of FIG. 2) and the electroadsorption deionization apparatus (100 of FIG. 2) according to an embodiment of the present invention and And / or the cathode (101b of FIG. 2). In this case, the electrochemically oxidized electrode (101a and / or 101b of FIG. 2) has high wettability and high specific surface properties as described above, thereby increasing the capacitance and lifespan characteristics of the electrode and hard water. The deionization rate of the influent and the regeneration rate of the electrode increases, leading to an increase in the performance of the electroadsorption deionization apparatus (100 in FIG. 2).

The electrochemical oxidation treatment of the electrode for an electroadsorption deionization apparatus according to an embodiment of the present invention may be performed using the electrosorption deionization apparatus 100 of FIG. 2 as well as the electrochemical cell 10 of FIG. 1. (See Examples 1 to 6).

2 is a schematic cross-sectional view of one embodiment of an electroadsorption deionization apparatus 100 having electrodes 101a and / or 101b in accordance with one embodiment of the present invention.

Referring to FIG. 2, an electroadsorption deionization apparatus 100 according to an embodiment of the present invention includes a pair of positive electrode 101a and a negative electrode 101b, a pair of current collectors 102a and 102b, and a separator 103. It can be provided. That is, the anode 101a and the cathode 101b are disposed on one surface and the other surface of the separator 103, respectively, and the current collector 102a is disposed on the surfaces opposite to the separator 103 of the anode 101a and the cathode 101b, respectively. ) And the current collector 102b may be disposed.

At least one electrode of the anode 101a and the cathode 101b may be an electrochemically oxidized electrode according to the aforementioned method. As an example, the anode 101a may include activated carbon that is not electrochemically oxidized, and the cathode 101b may include electrochemically oxidized high surface area graphite. As another example, the anode 101a and the cathode 101b may each include electrochemically oxidized activated carbon.

Inflow water (ex. Hard water) introduced into the apparatus 100 through one end of the separator 103 is deionized while passing through the apparatus 100 to be converted into treated water (ex. Soft water). It is discharged to the outside through the other end of the separator 103.

The pair of current collectors 102a and 102b supplies charge to the pair of electrodes 101a and 101b during charging (i.e., deionization of the influent) and discharges (i.e., electrode regeneration) to the pair of electrodes 101a and 101b. ) Is a passage for discharging the accumulated charge and is electrically connected to the power supply PS. The current collectors 102a and 102b may have one form selected from, for example, carbon plate, carbon paper, metal plate, metal mesh, and metal foam, and include aluminum, nickel, copper, titanium, stainless steel, iron, and the like. Mixtures or alloys of two or more of these may be included.

The separator 103 serves to secure a flow path between the pair of electrodes 101a and 101b stacked up and down, and to block electrical contact between the pair of electrodes 101a and 101b and the corresponding current collectors 102a and 102b. To carry out, for example, it may include an acrylic fiber, a polyethylene film and / or a polypropylene film.

Hereinafter, the operation and effects of the electroadsorption deionization apparatus 100 having the above configuration will be described in detail.

First, the deionization process (also called the charging process) of the influent proceeds as follows. Here, the influent is deionized and at the same time serves as an electrolyte of the electroadsorption deionization apparatus 100.

Inflow water flows into the device 100 through one end of the separator 103 in a state in which a DC voltage is applied to the pair of current collectors 102a and 102b by the power supply device PS. At this time, the positive electrode 101a electrically connected to the (+) pole of the power supply device PS through the current collector 102a is charged with (+), and through the current collector 102b of the power supply device PS. The negative electrode 101b electrically connected to the negative electrode is charged with negative (−). Referring to FIG. 2, the positive electrode 101a charged with (+) and the negative electrode 101b charged with (−) are disposed to face each other with the separator 103 interposed therebetween. Thus, anions such as harmful ions (Cl ⁻ ) contained in the influent are adsorbed on the positively charged anode 101a and cations such as hard water components (Ca ^{2 +} , Mg ^{2 +} ) are charged with (−). It is adsorbed by the cathode 101b. As the treatment time elapses, the anions and cations included in the influent are adsorbed on the anode 101a and the cathode 101b, respectively, and continue to accumulate. Therefore, the inflow water passing through the device 100 is deionized to be treated water, and the harmful temperature contained in the inflow water is removed. However, as the processing time elapses, the surface of each active material included in the electrodes 101a and 101b is covered with adsorbed cations or anions, thereby gradually decreasing the deionization efficiency of the influent. The deionization efficiency of such influent water can be confirmed by measuring the ionic conductivity of the treated water (ie, soft water) discharged from the apparatus 100 over time. In other words, if the ion conductivity of the treated water is low, it means that the amount of cation and anion contained in the influent water is high, so that the deionization efficiency is high. It means less deionization efficiency.

Therefore, when the ion conductivity of the treated water increases above a predetermined value, the electrodes 101a and 101b must be regenerated. That is, when the power supply to the device 100 is stopped and the device 100 is electrically shorted and discharged, the electrodes 101a and 101b lose their polarity, and thus the ions adsorbed on the active materials of the electrodes 101a and 101b. Will be removed. Thus, the active material of the electrodes 101a and 101b again recovers the active surface.

FIG. 2 shows only an electroadsorption deionization device having one separator, a pair of electrodes, and a pair of current collectors, but the present invention is not limited thereto, and another embodiment of the present invention is disclosed in Korean Patent Application No. 2008. An electroadsorption deionization apparatus identical to that disclosed in -0123154, and an electrosorption deionization apparatus similar to that disclosed in Korean Patent Application No. 2009-0077161, wherein at least one electrode of the pair of electrodes is electrochemically oxidized as described above. Device.

Hereinafter, the present invention will be described in detail with reference to the following examples, which are illustrative only and the present invention is not limited to the following examples.

Example

Example  1 ~ 6: electrosorption Deionization  Manufacturing of cells

1) Preparation of Electrode

① Preparation of Activated Carbon Electrode

45 g of activated carbon (PC of Osaka Gas), 5 g of carbon black (Timcal Super P), 8.3 g of 60% by weight polytetrafluoroethylene (PTFE) water suspension and 100 g of polyvinyl alcohol were added to the stirring vessel, and kneaded. And press molding. Thereafter, the resultant was dried in an oven at 80 ° C. for 2 hours, at 120 ° C. for 1 hour, and at 200 ° C. for 1 hour to complete an activated carbon electrode.

② Preparation of HSAG Electrode

45 g of high surface area graphite (Timcal's HSAG), 5 g of carbon black (Timcal's Super P), 60 wt% polytetrafluoroethylene (PTFE) water suspension and 100 g of polyvinyl alcohol were added and kneaded. After that, press molding was carried out. Thereafter, the resultant was dried in an oven at 80 ° C. for 2 hours, at 120 ° C. for 1 hour, and at 200 ° C. for 1 hour to complete an electrode.

2) Preparation of Electrochemically Oxidized HSAG Electrode

① PC electrode manufactured according to the process of 1) ①, and HSAG electrode prepared according to the process of 1) ② was cut into a size of 10cmx10cm (100cm2), respectively, to prepare two sheets.

② The two PC electrodes and two HSAG electrodes were put in distilled water and vacuum impregnated.

③ Current collector (graphite foil) → one sheet of HSAG electrode of ② → separator (polyester fiber: manufactured by Sefar) → one sheet of PC electrode of ② → current collector (graphite foil) cell) was prepared.

④ After putting 0.5MH ₂ SO ₄ aqueous solution or 0.5M KCl aqueous solution into the electrolytic cell as shown in Table 1 according to each embodiment, the cells were fastened.

5. The two electrodes of the electrochemical cell were charged with the constant current-constant voltage method. That is, after applying a constant current of 2A to the two electrodes, when the voltage reaches 3V, a constant voltage of 3V is applied to the two electrodes to charge the charge of 200 ~ 3,000C / g as shown in Table 1 according to each embodiment It was. In the charging, the HSAG electrode was used as a cathode, and the PC electrode was used as an anode.

⑥ The electrochemically oxidized HSAG electrode was washed with distilled water.

Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Electrolyte
(0.5M aqueous solution) H ₂ SO ₄ H ₂ SO ₄ H ₂ SO ₄ KCl KCl KCl Charge amount (C / g) 3,000 1,000 300 3,000 1,000 200

3) Preparation of Electrosorption Deionized Cell

Current collector (graphite foil) → HSAG electrode electrochemically oxidized in the above 2) → Separator (polyester fiber: manufactured by Sefar) → remaining one sheet of PC electrode of 2) ② → current collector (graphite foil) By lamination, an electroadsorption deionized cell was produced. In this electroadsorption deionized cell, the PC electrode was used as a cathode during deionization, and the electrochemically oxidized HSAG electrode was used as an anode.

Comparative example : Electrosorption Deionization  Manufacturing of cells

After the electrochemically oxidized HSAG electrode and PC electrode were prepared in the same manner as in Example, the PC electrode was used as a cathode during deionization, and the electrochemically oxidized HSAG electrode was used as an anode. An electroadsorption deionized cell was prepared in the same manner as in Example.

Evaluation example

Evaluation example  1: electrochemically oxidized HSAG  Evaluation of oxidation degree of electrode

The electrochemically oxidized HSAG electrodes prepared in Examples 1 and 4, and the electrochemically non-oxidized HSAG electrodes prepared in Comparative Example were placed in deionized water, and then stirred at 150 rpm for 4 days to prepare the HSAG electrodes. The functional group attached to the surface was desorbed. Thereafter, the deionized water washed with the HSAG electrode was titrated with 0.01 M NaOH aqueous solution, and the amount of NaOH used for the titration was shown in Table 2 below.

Example 1 Example 4 Comparative example Amount of NaOH used for titration (mmol / g) 2.213 1.105 0.383

Referring to Table 2, the electrochemically oxidized HSAG electrodes prepared in Examples 1 and 4, respectively, have more acidic functional groups than the electrochemically oxidized HSAG electrodes prepared in Comparative Examples, Therefore, it can be seen that the high hydrophilicity.

Evaluation example  2: electrochemically oxidized HSAG  Electrode Contact angle  evaluation

Electrochemically oxidized HSAG electrodes prepared in Examples 1 and 4, and non-chemically oxidized HSAG electrodes prepared in Comparative Example, respectively, in contact with hard water (IEC 60734 standard hard water), a contact angle measuring instrument Using the (Kruss DSA 10), the hard water and each HSAG electrode was photographed in contact with each other are shown in Figs.

3A and 3B are photographs showing the hard water contacted with the electrochemically oxidized HSAG electrodes prepared in Examples 1 and 4, respectively, and FIG. 3C is an electrochemical prepared in Comparative Example. The photo shows the non-oxidized HSAG electrode and the hard water contacting each other.

Example 1 Example 4 Comparative example Contact angle (°) 96 94 122

3A to 3C and Table 3, the electrochemically oxidized HSAG electrodes prepared in Examples 1 and 4, respectively, have a contact angle higher than that of the electrochemically oxidized HSAG electrodes prepared in Comparative Examples. It can be seen that it is small and therefore high hydrophilicity.

Evaluation example  3: Evaluation of Life Characteristics of Cell Electrode

Each of the electrosorption deionized cells prepared in Examples 1 to 6 and Comparative Examples was operated under the following conditions, and the ion conductivity of the effluent (ie, treated water during charging or waste water during discharge) according to the treatment time (Example 1, Example 4 and Comparative Example), the charge amount (Examples 1 to 6 and Comparative Example) according to the number of charge cycles, the discharge rate (Example 1, Example 4 and Comparative Example) with time by measuring the 5a, 5b ~ 7a and 7b are respectively shown graphically.

(1) Operation of the cell was performed at room temperature with the electrode submerged in the electrolyte.

② Inflow water was used as IEC 60734 standard hard water, and the flow rate was maintained at 30 mL / min.

③ Charged with a constant voltage (2.0V) for 10 minutes, and then electrically shorted for 20 minutes.

The filling amount is a value calculated by Equation 1 shown in FIG. 4. 4 is a diagram illustrating a method of obtaining a charge amount and a discharge amount by showing a change in ion conductivity of effluent water according to a treatment time when treating influent water using a conventional electroadsorption deionizer. This amount of charge is proportional to the amount of deionization in the influent water by the cell.

[Equation 1]

Charge amount = (Ion conductivity of influent measured before cell passing * Charge time)-(Integrated ion conductivity curve of effluent with time over actual charge time).

On the other hand, the discharge amount is a value calculated by the following equation (2), and is shown in FIG. This discharge amount is proportional to the ion desorption rate from the electrode.

[Equation 2]

Discharge amount = (Integrated ion conductivity curve of effluent over time during actual discharge time)-(Ion conductivity of influent measured before cell passing * discharge time).

Figures 5a and 5b is the electrode according to the prior art to change the ion conductivity of the effluent according to the treatment time when the deionization of the influent using an electroadsorption deionizer comprising an electrode according to an embodiment of the present invention, respectively It is a graph compared with the electroadsorption deionization apparatus including a. 5A and 5B, the concave peak is the charge peak and the convex peak is the discharge peak.

5A and 5B, in Examples 1 and 4, the ion conductivity of the treated water drops sharply to a very low level during charging, and the ion conductivity of the wastewater is very high during discharge. It appeared to increase rapidly. From these results, it can be seen that Example 1 and Example 4, compared with the comparative example, the amount of ion removal in the influent, the deionization rate and the regeneration rate of the electrode is faster.

6A and 6B illustrate an electrode according to the prior art for changing the amount of charge according to the number of charge cycles when deionization of influent water is performed using an electroadsorption deionization apparatus including an electrode according to an embodiment of the present invention. It is the graph shown compared with the electrosorbing deionizer containing.

6A and 6B, each of the electroadsorption deionizers prepared in Examples 1 to 6 was found to have a larger amount of charge than the electroadsorption deionizer produced in the comparative example. The larger the charge amount, the higher the deionization rate and the deionization amount. In addition, it can be seen that each of the electroadsorption deionizers prepared in Examples 4 to 6 shows a slight decrease in the charge amount even if the number of charges is increased, so that the life characteristics of the electrode are excellent.

6A and 6B summarized once the amount of charge separately shown in Table 4 below.

Example  One Example  2 Example  3 Example  4 Example  5 Example  6 Comparative example Charge (uS Sec Of cm ) 2,257,000 2,257,000 1,512,000 1,967,000 1,595,000 1,381,000 1,199,000 opponent
Charge amount (%)
( Comparative Example  Charge level) 188 188 126 164 133 115 100

Referring to Table 4, it was found that the charge amount at the time of one charge was 1.15 to 1.88 times the level of Comparative Examples 1-6.

7A and 7B illustrate the electrode according to the prior art for changing the discharge rate with time when deionization of influent water is performed using an electroadsorption deionization apparatus including an electrode according to an embodiment of the present invention, respectively. It is a graph shown in comparison with the electrosorption deionization apparatus. Here, the 'discharge rate' means a value obtained by dividing the discharge amount per unit time by the total discharge amount.

7A and 7B, each of the electroadsorption deionizers prepared in Examples 1 and 4 was found to have a faster discharge rate than the electroadsorption deionizers prepared in Comparative Example. The faster the discharge rate, the faster the regeneration rate of the electrode, and the amount of influent water consumed to regenerate the electrode is reduced.

Although the preferred embodiment according to the present invention has been described above with reference to the accompanying drawings, this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Could be. Therefore, the protection scope of the present invention should be defined by the appended claims.

10: electrochemical cell 11: reaction vessel
12: electrolyte solution 13a, 101a: anode
13b, 101b: cathode 14, 103: separator
100: electroadsorption deionizer 102a, 102b: current collector

Claims (17)

A method for producing an electrode for an electroadsorption deionization device comprising electrochemically oxidizing an electrode comprising a hydrophobic active material. The method of claim 1,
The electrode is a method of manufacturing an electrode for an electroadsorption deionizer further comprising a binder and a conductive agent. The method of claim 2,
The electrode is a method of manufacturing an electrode for an electroadsorption deionization device manufactured using a hydrophobic active material in the form of a powder. The method of claim 1,
The hydrophobic active material is a method for producing an electrode for an electroadsorption deionizer comprising a carbon material. The method of claim 4, wherein
The carbon material is a method for producing an electrode for an electroadsorption deionization device comprising at least one selected from the group consisting of activated carbon, carbon nanotubes (CNT), mesoporous carbon, activated carbon fibers, graphite and graphite oxide. . The method of claim 5,
And said graphite comprises high surface area graphite (HSAG). The method of claim 1,
The electrochemical oxidation of the electrode is made in an electrochemical cell comprising the electrode, the counter electrode, the electrolyte in which these electrodes are locked, and a separator that electrically insulates the electrode from the counter electrode,
In the electrochemical cell, the electrode acts as a cathode and the corresponding electrode acts as an anode. The method of claim 7, wherein
The electrode and the corresponding electrode is the same or different method for producing an electrode for an electroadsorption deionization device. The method of claim 7, wherein
The electrolytic solution is a method of producing an electrode for an electroadsorption deionization device is an acidic, alkaline or neutral solution. The method of claim 7, wherein
In the step of electrochemical oxidation of the electrode, the amount of charge charged in the electrochemical cell is 20 ~ 30,000C / g The method of manufacturing an electrode for an electroadsorption deionizer. The method of claim 7, wherein
The electrochemical oxidation of the electrode, the contact angle between the electrode and the hydrophilic electrolyte is reduced, the manufacturing method of the electrode for electrosorption deionization device. The method of claim 1,
The method of manufacturing an electrode for an electroadsorption deionization device further comprising the step of washing the electrochemically oxidized electrode with a washing liquid. An electrode for an electroadsorption deionization device comprising an electrochemically oxidized active material. The method of claim 13,
An electrode for an electroadsorption deionizer comprising an acidic functional group. The method of claim 14,
The amount of the acidic functional group per unit weight of the electrode is an electrode for electroadsorption deionization device is 0.7 ~ 5mmol / g. The method of claim 14,
And said acidic functional group comprises at least one selected from the group consisting of a carboxyl group (COOH), a lactone group (COO) and a phenol group. Electrosorption deionization apparatus provided with the electrode as described in any one of Claims 13-16.

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