CN115893602B - Capacitive deionization system capable of reinforcing electrode material by electrolyte - Google Patents

Abstract

The invention discloses a capacitive deionization system capable of reinforcing electrode materials by means of electrolyte, which comprises an anode chamber, a cathode chamber and a brine chamber, wherein an anion exchange membrane close to the anode chamber and a cation exchange membrane close to the cathode chamber are arranged between the anode chamber and the cathode chamber, a manganese dioxide electrode plate is arranged in the anode chamber and is filled with ammonium chloride solution, an active carbon electrode plate is arranged in the cathode chamber and is filled with sodium ferricyanide solution; the cation exchange membrane and the anion exchange membrane are separated by a chamber between two adjacent ion exchange membranes in the pair to form a brine chamber, and the brine chamber forms a closed loop by using a silica gel tube. According to the invention, functional interfaces are constructed by respectively utilizing the sodium ferricyanide solution reinforced active carbon electrodes in the cathode chamber to cooperatively adsorb more sodium ions, and the ammonium chloride solution reinforced MnO ₂ electrodes in the anode chamber cause hydrogen bond breakage to cooperatively adsorb more chloride ions, so that the desalting performance is improved.

Description

A capacitive deionization system capable of strengthening its electrode materials with the help of electrolyte

Technical Field

The invention belongs to the technical field of salt water desalination, and relates to a capacitive deionization system capable of strengthening its electrode material with the aid of electrolyte.

Background Art

Given the abundant seawater and brackish water resources on the earth, converting seawater into fresh water through desalination technology is an effective way to solve this problem. Common seawater desalination strategies usually include reverse osmosis, thermal distillation, electrodialysis and capacitive deionization (CDI). Reverse osmosis, thermal distillation and electrodialysis have been widely used around the world, and the demand is still growing. However, these three methods are accompanied by high energy consumption. As an alternative solution, CDI is easy to operate and environmentally friendly, and its low energy consumption provides a sustainable future for seawater desalination. CDI removes ions from brine based on electrical absorption on the electrode surface. The ions are collected and stored in the double layer, but its low capacitance leads to relatively low desalination.

After a lot of research, it was found that hybrid capacitive deionization (HCDI) has a higher desalination capacity, in which the Faraday electrode captures sodium ions on one side and the carbon-based material is located on the other side to physically absorb chloride ions, but it still has some thresholds because its desalination method relies on the removal of ions through the electrical adsorption of the bulk material and the Faraday reaction. Therefore, in order to increase the desalination capacity, it is necessary to break these thresholds through the research and improvement of electrode materials and electrolytes. At present, no researchers have studied its threshold and its performance improvement through electrolytes.

Summary of the invention

The present invention aims to provide a capacitive deionization system capable of strengthening its electrode materials with the help of electrolytes to overcome the problems mentioned in the background technology. The system comprises an anode chamber, a cathode chamber and a brine chamber. The activated carbon electrode is strengthened with a sodium ferrocyanide solution in the cathode chamber to construct a functional interface to synergistically adsorb more sodium ions, and the _MnO2 electrode is strengthened with an ammonium chloride solution in the anode chamber to cause hydrogen bond breaking to synergistically adsorb more chloride ions, thereby improving the desalination performance of CDI.

The technical solution of the present invention is as follows:

A capacitive deionization system capable of strengthening its electrode material with the aid of an electrolyte comprises an anode chamber, a cathode chamber and a brine chamber, wherein an anion exchange membrane close to the anode chamber and a cation exchange membrane close to the cathode chamber are arranged between the anode chamber and the cathode chamber, a manganese dioxide electrode sheet is arranged in the anode chamber and is injected with an ammonium chloride solution with a concentration of 0.01 mol/L, and an activated carbon electrode sheet is arranged in the cathode chamber and is injected with a sodium ferrocyanide solution with a concentration of 0.01 mol/L; two adjacent ion exchange membranes in the cation exchange membrane and the anion exchange membrane pair are separated by a chamber to form a brine chamber, and the brine chamber forms a closed loop using a silicone tube; the manganese dioxide electrode sheet is connected to the activated carbon electrode sheet through a wire via an external voltage, and the anode chamber and the cathode chamber are connected using a silicone tube to form a closed loop.

As a limitation of the present invention:

(1) The manganese dioxide electrode sheet is prepared in the following steps:

S1. Preparation of manganese dioxide with ammonium ion hydrogen bond pre-intercalation

S11, dissolving sodium permanganate and ammonium sulfate in deionized water to form sodium permanganate solution and ammonium sulfate solution, respectively, mixing the sodium permanganate and ammonium sulfate solutions at a molar ratio of 2:1 and stirring them magnetically to obtain a mixed solution;

S12, transferring the obtained mixed solution to a reaction kettle and reacting it at 170-190° C. for 16 h, and cooling it to room temperature after the reaction is completed to obtain a suspension;

S13, centrifuging and washing the suspension three times respectively, and then placing the solid product in a freeze drying oven for freeze drying to obtain α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation;

S2. Preparation of manganese dioxide electrode sheet

The product prepared in step S1 was ground into powder, and the powder was evenly mixed with acetylene black, polyvinyl butyral and polyvinyl pyrrolidone to obtain a mixture, and then anhydrous ethanol was added to the mixture, stirred for 20 minutes to obtain a slurry mixture, and the slurry mixture was evenly applied on a graphite plate, and dried at 80° C. to obtain a manganese dioxide electrode sheet.

(ii) The activated carbon electrode sheet is prepared in the following steps:

The activated carbon was ground into powder and mixed evenly with acetylene black, polyvinyl butyral and polyvinyl pyrrolidone to obtain a mixture, and then anhydrous ethanol was added to the mixture and stirred for 20 minutes to obtain a slurry mixture. The slurry mixture was evenly applied on a graphite plate and dried at 80°C to obtain an activated carbon electrode sheet.

As a further limitation of the present invention:

(i) In step S13, the freeze-drying temperature is -60°C and the time is 12 hours.

The freeze-drying process affects the evaporation rate of water in the material and the strength of the material. Freeze-drying keeps its volume almost unchanged, maintains the original pore structure, and does not cause concentration. The special pore structure not only ensures its stability, but also further promotes charge transfer.

(ii) In step S2, the mass ratio of the α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation layer to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone is 20:8.6:5:7.5.

The mass ratio of the α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation layer to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone in the present invention affects the conductivity and ion diffusion of the active material, and further affects the desalination performance and rate performance of the active material.

(iii) In step S2, the slurry mixture is evenly applied on the graphite plate with a thickness of 0.3-0.5 mm.

As a further limitation of the present invention:

(i) The mass ratio of activated carbon to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone is 20:8.6:5:7.5.

(ii) The slurry mixture is evenly applied on the titanium plate with a thickness of 0.3-0.5 mm.

The present invention also has a limitation that the α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation is in the form of nanorods with a pore diameter of 50 nm. This special pore structure is beneficial for expanding the contact area between the electroactive material and the electrolyte ammonium ions, promoting the storage and diffusion of ammonium ions, and alleviating the structural changes caused by ion insertion/ejection during the discharge/charge process. The α-phase manganese dioxide with ammonium ion pre-intercalation of a smaller molar mass has hydrogen bonds formed between ammonium ions and oxygen atoms, and the strong bond energy prevents structural collapse, and acts as a "structural column" to stabilize the pore structure and provide high cycle performance.

The present invention provides a capacitive deionization system capable of strengthening its electrode material with the aid of an electrolyte, wherein the activated carbon electrode is strengthened with a sodium ferrocyanide solution in a cathode chamber to synergistically adsorb more sodium ions, and the ammonium chloride solution in an anode chamber is strengthened with an _MnO2 electrode to synergistically adsorb more chloride ions, thereby improving the desalination performance of the system. Specifically, in the anode chamber, while the activated carbon uses a double electric layer to adsorb sodium ions, sodium ferrocyanide undergoes a reduction reaction, and the sodium ferrocyanide and the activated carbon electrode sheet increase the contact area and effectively construct a functional interface, thereby synergistically adsorbing more sodium ions; in the cathode chamber, because an α-phase manganese dioxide electrode sheet with ammonium ion hydrogen bond pre-intercalation is used, hydrogen bonds are formed between ammonium ions and manganese dioxide to promote charge transfer and further stabilize the structure. Due to its special structure, during the electrolysis process, the manganese dioxide with ammonium ion hydrogen bond pre-intercalation uses the breaking of hydrogen bonds in the ammonium chloride electrolyte to transfer a large amount of electrons to adsorb chloride ions, because the breaking of hydrogen bonds can transfer more electrons, so that it adsorbs more chloride ions, thereby achieving a significant desalination performance.

In the electrolysis system of the present invention, the concentrations of ammonium chloride in the anode chamber and sodium ferrocyanide in the cathode chamber are also relatively important. The best effect is achieved when the electrolyte concentration is 0.01 mol/L. When the concentration is lower than this, the performance will be reduced due to insufficient ferrocyanide reducing ability and insufficient number of broken hydrogen bonds. When the concentration is too high, it will not only lead to waste of electrolyte, but also may cause further performance degradation due to increased system resistance due to ion polarization of the intermediate salt solution. Most importantly, sodium ferrocyanide will eventually not only cause environmental impacts of harmful chemicals, but also lead to high maintenance costs.

The above technical solution of the present invention is taken as a whole, and each step is closely related and cannot be separated.

After adopting the above technical solution, the beneficial effects achieved by the present invention are as follows:

1. The preparation method is simple, the process is easy to control, and it is easy to promote and apply industrially. This systematic improvement will make the CDI system practical in subsequent research.

2. The system exhibits excellent desalination performance in high-concentration salt water or even seawater environments, and has great potential for large-scale desalination.

The specific implementation of the present invention will be further described in detail below with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG1 is an X-ray diffraction pattern of manganese dioxide with ammonium ion hydrogen bond pre-intercalation;

FIG2 is an infrared spectrum of manganese dioxide with ammonium ion hydrogen bond pre-intercalation;

FIG3 is a transmission electron micrograph of manganese dioxide with ammonium ion hydrogen bond pre-intercalation;

FIG4 is a graph showing the desalination performance of the CDI system and HCDI of the electrolyte-enhanced electrode material at different voltages;

Figure 5 Desalination principle of CDI system with electrolyte-enhanced electrode materials;

FIG6 is a CV graph of sodium ferrocyanide enhanced activated carbon electrode and activated carbon electrode;

FIG7 is a CV graph of an ammonium chloride solution-enhanced manganese dioxide electrode and a manganese dioxide electrode;

FIG8 is a cycle diagram of the desalination performance of the desalination system CDI of the present invention at a voltage of 1.2V.

DETAILED DESCRIPTION

In the following examples, the reagents described are all commercially available unless otherwise specified, and the following experimental methods and detection methods are all existing experimental methods and detection methods unless otherwise specified.

Example 1 A capacitive deionization system capable of strengthening its electrode material with the aid of an electrolyte

The present embodiment is a capacitive deionization system capable of strengthening its electrode material with the aid of an electrolyte, the system comprising an anode chamber, a cathode chamber and a brine chamber, a cation exchange membrane close to the anode chamber and an anion exchange membrane close to the cathode chamber are arranged between the anode chamber and the cathode chamber, a manganese dioxide electrode sheet is arranged in the anode chamber and is injected with a 0.01 mol/L ammonium chloride solution (as an electrolyte), an activated carbon electrode sheet is arranged in the cathode chamber and is injected with a 0.01 mol/L sodium ferrocyanide solution (as an electrolyte); a chamber is provided between two adjacent ion exchange membranes in the cation exchange membrane and the anion exchange membrane to form a brine chamber (the brine chamber contains brine to be desalted), and the brine chamber forms a closed loop using a silicone tube. The manganese dioxide electrode sheet is connected to the activated carbon electrode sheet through a wire via an external voltage, and the anode chamber and the cathode chamber are connected using a silicone tube to form a closed loop.

1. The manganese dioxide electrode sheet used in the above system is prepared in the following steps:

S1. Preparation of manganese dioxide with ammonium ion hydrogen bond pre-intercalation

S11, dissolving sodium permanganate and ammonium sulfate in deionized water to form sodium permanganate solution and ammonium sulfate solution, respectively, mixing the sodium permanganate and ammonium sulfate solutions at a molar ratio of 2:1 and stirring them magnetically to obtain a mixed solution;

S12, transferring the obtained mixed solution to a reaction kettle and reacting it at 170° C. for 16 h, and cooling it to room temperature after the reaction is completed to obtain a suspension;

S13, the suspension was centrifuged and washed with water three times respectively, and then the solid product was placed in a freeze drying box and freeze-dried at a temperature of -60 ° C for 12 hours to obtain an α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation, and the α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation was a nanorod morphology with a pore diameter of 50nm. Figures 1 and 2 are respectively the X-ray diffraction diagram and infrared spectrum diagram of the prepared manganese dioxide of this structure, and Figure 1 provides information about the crystal structure of the material, and all diffractions can be attributed to α-MnO ₂ (JCPDS card number 44-0141). The peak of wave number 1400cm ^-1 in Figure 2 is attributed to the in-plane bending vibration of NH, and the peaks of 2850cm ^-1 and 2920cm ^-1 are respectively the stretching vibrations of NH ... O and NH, which are the evidence of the formation of hydrogen bonds by ammonium root intercalation. These two characterizations prove the successful synthesis of manganese dioxide with ammonium ion hydrogen bond pre-intercalation. FIG3 is a transmission electron microscope image of the product, from which it can be seen that the synthesized manganese dioxide has a nanorod morphology and shows a one-dimensional shape with a flat end of the nanorod.

S2. Preparation of manganese dioxide electrode sheet

The product prepared in step S1 is ground into powder, and the powder is evenly mixed with acetylene black, polyvinyl butyral and polyvinyl pyrrolidone to obtain a mixture, wherein the mass ratio of α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone is 20:8.6:5:7.5; then anhydrous ethanol is added to the mixture, stirred for 20 minutes, to obtain a slurry mixture, the slurry mixture is evenly applied on a graphite plate with a thickness of 0.3-0.5 mm, and dried at 80° C. to obtain a manganese dioxide electrode sheet.

2. The activated carbon electrode sheet used in the above system is prepared in the following order:

The activated carbon was ground into powder, and the powder was evenly mixed with acetylene black, polyvinyl butyral and polyvinyl pyrrolidone to obtain a mixture, wherein the mass ratio of the activated carbon to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone was 20:8.6:5:7.5; then anhydrous ethanol was added to the mixture, stirred for 20 minutes to obtain a slurry mixture, the slurry mixture was evenly applied on a graphite plate with a thickness of 0.3-0.5 mm, and dried at 80° C. to obtain an activated carbon electrode sheet.

The capacitive desalination system of this embodiment was powered on for capacitive deionization, and a sodium chloride aqueous solution was used as a model system to simulate brackish water with sodium chloride as the main salt component. In a sodium chloride solution with an initial concentration of 500 mg/L, the adsorption amount of the electrolyte-enhanced electrode material in the system shown in this embodiment was evaluated at different voltages, and the experimental results are as follows:

It can be observed from FIG. 4 that the desalination capacity of the system is significantly enhanced, which is mainly attributed to the reaction mechanism shown in FIG. 5 in the charging step: the cathode chamber obtains more electrons by adsorption of activated carbon and reduction of sodium ferrocyanide. In the case of 1 mol/L sodium chloride solution and the presence of a redox couple, the CV curve shows obvious redox peaks near 0.12 and 0.28 V (vs Ag/AgCl), while in the absence of a redox couple, the CV has a rectangular shape (as shown in FIG. 6). This situation occurs due to the presence of the cation exchange membrane, which can only capture more sodium ions to achieve charge balance. At the same time, the manganese dioxide with ammonium ion hydrogen bond pre-intercalation in the anode chamber loses more electrons by breaking the hydrogen bond. In the case of 1 mol/L ammonium chloride as the electrolyte, the CV curve shows obvious redox peaks near -0.08 and 0.38 V (vs Ag/AgCl), while when the electrolyte is 1 mol/L sodium chloride, the CV has a rectangular shape (as shown in FIG. 7). Also due to the presence of the anion exchange membrane, ammonium ions cannot leave the cathode chamber, and more chloride ions will be captured to achieve charge balance. Thus, the reduction of ferrocyanide and the breaking of hydrogen bonds are believed to be the main reasons for the enhanced desalination performance observed in this system.

At a voltage of 1.2 V, the reduction reaction and the breaking of hydrogen bonds increased the desalination to 51.5 mg/g, compared with the desalination of 27.7 mg/g in the conventional CDI. In the discharge step, the ions released from the anode and cathode chambers move to the intermediate salt solution to meet the electrical neutrality in the anode and cathode chambers. In addition, FIG8 is a desalination performance diagram of 100 cycles and the initial performance. It can be found from FIG8 that the desalination system of this embodiment remains stable after undergoing 100 complete ion storage/release processes at a voltage of 1.2 V, indicating that its cycle stability is good.

Example 2: The desalination advantages of α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation as the anode of the desalination system in this system

In this embodiment, the desalination performance of manganese dioxide with different structures as the anode material of the desalination system is studied. The capacitive desalination reaction system is tested for desalination at a voltage of 1.2 V. The test process is the same as that in Example 1. The specific system structure composition and the electrode preparation method are similar to those in Example 1. The only difference is that the manganese dioxide of the anode material is different, as shown in the following table.

Table 1 Effect of different manganese dioxide on desalination performance in this system

It can be observed from the table that the cycle performance of the α-phase manganese dioxide desalination with ammonium ion hydrogen bond pre-intercalation is superior, while the cycle retention rate of the α-phase manganese dioxide without ammonium ion hydrogen bond pre-intercalation and the δ-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation prepared by a method similar to Example 1 is relatively poor. This is because the ammonium ions in the α-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation form hydrogen bonds with oxygen atoms, which can act as "structural columns" to stabilize the pore structure. The special pore structure can not only promote the storage and diffusion of ammonium ions, but also help to alleviate the structural changes caused by ion insertion/extraction during discharge/charging, thereby providing high cycle performance.

Example 3 Study on the influence of different electrolyte solutions in the anode chamber on the desalination performance of the desalination system

In this embodiment, the effects of different electrolyte solutions in the anode chamber on the delay performance of the desalination system are studied and tested. The desalination reaction system is tested at a voltage of 1.2V. The test process is the same as that in Example 1. The specific structure and composition of the desalination system and the preparation method of the electrode are similar to those in Example 1. The only difference is that the electrolyte solution in the anode chamber is different, as shown in the following table.

Table 2 Effect of different electrolyte solutions in the anode chamber on desalination performance in this system

From the desalination test results, when the salt solution in the anode chamber is ammonium chloride, the desalination performance is the highest. The manganese dioxide with an intercalated structure prepared by the present invention utilizes the breaking of hydrogen bonds in the ammonium chloride electrolyte to transfer a large amount of electrons to adsorb chloride ions, while other salt solutions cannot form hydrogen bonds with manganese dioxide, resulting in a lower desalination amount.

Example 4 Desalination performance test at different applied voltages during desalination electrolysis

This example conducted a series of experimental studies on the desalination voltage applied to the desalination system prepared in Example 1, and the specific results are as follows:

Table 3 Effect of applied voltage on desalination performance in this system

The specific results are shown in Figure 4. From the effluent distribution diagram in the figure, the increase in voltage leads to the amplification of the conductivity curve obtained from the effluent of the middle channel. Figure 4 shows that the desalination amount increases from 23.0 mg/g (at a voltage of 0.4 V) to 51.5 mg/g (at a voltage of 1.2 V), which means that sufficient voltage is required to fully utilize the charge transfer caused by the reduction reaction of ferrocyanide and the breaking of hydrogen bonds.

Example 5 Comparative Example

The following groups prepared different capacitive desalination systems, as follows:

Group A: Example 1.

Group B: HCDI system, specifically a CDI system composed of activated carbon and manganese dioxide, which is similar to the desalination system of Example 1, except that no electrolyte is used to strengthen the activated carbon electrode and the manganese dioxide electrode.

Group C: Similar to Example 1, except that the electrolyte sodium ferrocyanide was not added to the cathode chamber, but sodium chloride was added instead.

Group D: Similar to Example 1, except that the electrolyte ammonium chloride was not added to the anode chamber, and sodium chloride was added instead.

Group E: Similar to Example 1, except that no activated carbon was added to the cathode chamber, and electrolyte sodium ferrocyanide was directly added.

Group F: Similar to Example 1, except that the electrolyte concentrations in the cathode and anode chambers were both 0.001 mol/L.

Group J: Similar to Example 1, except that the electrolyte concentration in the cathode/anode compartments was 0.05 mol/L.

Desalination electrolysis tests were performed on the above groups respectively, and the test process was the same as in Example 1, wherein the results of Group A-B are shown in FIG4 .

The desalination results of groups C-J are shown in the table below.

Table 4 Desalination performance of different comparative examples in this system

From the desalination test results of this embodiment, in the proposed system, the sodium ferrocyanide solution in the cathode chamber strengthens the activated carbon electrode to construct a functional interface to synergistically adsorb more sodium ions, and the ammonium chloride solution in the anode chamber strengthens the _MnO2 electrode with an intercalated structure, causing the hydrogen bonds to break and synergistically adsorb more chloride ions. The two complement each other, allowing the desalination performance of CDI to break through its own threshold and reach 51.5 mg/g. When the electrolyte concentration is 0.01 mol/L, the interaction between the material and the electrolyte can be maximized without causing waste of resources.

Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of protection of the claims of the present invention.

Claims (6)

1. The capacitive deionization system capable of strengthening electrode materials by means of electrolyte comprises an anode chamber, a cathode chamber and a brine chamber, wherein an anion exchange membrane close to the anode chamber and a cation exchange membrane close to the cathode chamber are arranged between the anode chamber and the cathode chamber; the concentrations of the ammonium chloride solution and the sodium ferricyanide solution are 0.01 mol/L; the cation exchange membrane and the anion exchange membrane are separated from each other by a chamber between two adjacent ion exchange membranes in the pair to form a brine chamber, and the brine chamber forms a closed loop by using a silica gel tube; the manganese dioxide electrode plate is connected with the active carbon electrode plate through an external voltage by a lead, the desalination voltage is 1.2V, and the anode chamber and the cathode chamber are connected by a silica gel tube to form a closed loop;

the manganese dioxide electrode plate is prepared sequentially according to the following steps:

S1, preparing manganese dioxide with ammonium ion hydrogen bond pre-intercalation

S11, respectively dissolving sodium permanganate and ammonium sulfate in deionized water to respectively form sodium permanganate and ammonium sulfate solutions, and magnetically stirring the sodium permanganate and the ammonium sulfate solutions after mixing according to the mass molar ratio of 2:1 to obtain a mixed solution;

s12, transferring the obtained mixed solution into a reaction kettle, reacting at 170-190 ℃ for 16 h, and cooling to room temperature after the reaction is finished to obtain a suspension;

S13, respectively centrifuging and washing the suspension for three times, and then freeze-drying the solid product in a freeze-drying box to obtain alpha-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation;

The alpha-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation is in a shape of a nano rod, and the diameter of a pore canal is 50 nm;

S2, preparing manganese dioxide electrode plate

Grinding the product prepared in the step S1 into powder, uniformly mixing the powder with acetylene black, polyvinyl butyral and polyvinylpyrrolidone to obtain a mixture, adding absolute ethyl alcohol into the mixture, stirring 20 min to obtain a slurry mixture, uniformly coating the slurry mixture on a graphite plate, and drying at 80 ℃ to obtain a manganese dioxide electrode slice;

In the step S2, the mass ratio of alpha-phase manganese dioxide with ammonium ion hydrogen bond pre-intercalation to acetylene black, polyvinyl butyral and polyvinylpyrrolidone is 20:8.6:5:7.5.

2. A capacitive deionization system capable of reinforcing an electrode material thereof by means of an electrolyte according to claim 1, wherein said activated carbon electrode sheet is prepared by sequentially following the sequence of steps:

Grinding activated carbon into powder, uniformly mixing the powder with acetylene black, polyvinyl butyral and polyvinylpyrrolidone to obtain a mixture, adding absolute ethyl alcohol into the mixture, stirring the mixture for 20 min to obtain a slurry mixture, uniformly coating the slurry mixture on a graphite plate, and drying the mixture at 80 ℃ to obtain the activated carbon electrode slice.

3. A capacitive deionization system capable of reinforcing electrode materials thereof by means of an electrolyte as claimed in claim 1, wherein in step S13, the temperature of said freeze-drying is-60 ℃ for a time of 12 h.

4. A capacitive deionization system capable of reinforcing electrode materials thereof by means of an electrolyte as claimed in claim 1, wherein said slurry mixture is uniformly applied to graphite plates in a thickness of 0.3 to 0.5mm a in step S2.

5. A capacitive deionization system capable of reinforcing electrode materials thereof by means of an electrolyte according to claim 2, wherein the mass ratio of activated carbon to acetylene black, polyvinyl butyral and polyvinyl pyrrolidone is 20:8.6:5:7.5.

6. A capacitive deionization system capable of reinforcing electrode materials thereof by means of an electrolyte as claimed in claim 2, wherein said slurry mixture is uniformly applied to a graphite sheet with a thickness of 0.3 to 0.5mm a.