KR20130107845A - Manufacturing device of electrolyte solution for vanadium redox flow battery using electrolysis and manufacturing method of the same - Google Patents

Abstract

The present invention relates to an apparatus and a method for producing an electrolyte solution for VRB, and more particularly, to a cathode active material containing V ^{2 +} , V ^{3 +} , V ^{4 +} , V ^{5 +} To an apparatus and a method for manufacturing an electrolyte solution for VRB using electrolysis capable of producing an anolyte solution.
An electrolytic solution producing apparatus for VRB using electrolysis according to the present invention is characterized by comprising a cathode for primary electrolysis, a cathode for primary electrolysis, a cathode for cathode for electrolysis, a power supply for supplying power to the cathode for cathodic electrolysis, A primary electrolytic apparatus including a primary electrolytic catholyte and a primary electrolytic catholyte, a separator for separating the primary electrolytic catholyte and the primary electrolytic catholyte, a primary electrolytic catholyte and a sulfuric acid solution in which vanadium oxide is dissolved in the primary electrolytic catholyte, A secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly and a power supply device for supplying power to the secondary electrolytic cathodic assembly, a secondary electrolytic cathodic assembly and a secondary electrolytic cathodic assembly A secondary electrolytic apparatus including a secondary catholyte electrolytically decomposed in the primary electrolytic catholyte in the secondary electrolytic catholyte and the secondary catholyte in the secondary electrolytic catholyte, Bipolar plates, oxidation of the third anolyte A first carbon felt electrode for causing a reduction reaction with the first carbon felt electrode, a positive electrode electrolytic space formed by a positive electrode electrolyte flow frame, a second bipolar plate for performing a current collecting function, a second carbon felt electrode for causing oxidation reaction and reduction reaction of the third negative electrode liquid A negative electrode electrolytic space comprising a negative electrode electrolyte flow frame, an ion exchange membrane for separating the positive electrode electrolytic space and the negative electrode electrolytic space, a power supply for supplying power to the cell, and a resistor for inducing discharge in the cell The present invention also provides an apparatus for producing an electrolyte solution for VRB using electrolysis.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to an apparatus for manufacturing an electrolyte for VRB using electrolysis,

The present invention vanadium redox flow battery; and a, more particularly, sulfuric vanadium oxide (VOSO ₄₎ as to the production apparatus and production method of the electrolytic solution for (Vanadium Redox Flow Battery VRB) in the starting material V ^{2 +,} V ^{3 +} , V ^{4 +} , V ^{5 +} ions, and an electrolytic solution capable of producing an anolyte solution, and a manufacturing method thereof.

With the development of transportation and communication, energy demand is increasing worldwide. Continued use of fossil fuels due to this increase in energy demand has resulted in the continual release of carbon dioxide, resulting in environmental pollution.

Carbon dioxide emitted as such is a greenhouse gas, and is cited as the main cause of global warming. Humans are trying to develop various kinds of energy such as solar energy, wind power, and fuel cell to suppress the above-mentioned emission of greenhouse gas.

Since renewable energy such as solar power and wind power is greatly influenced by location environment and natural conditions, it is difficult to supply continuously due to fluctuation of output, and there is a time lag between energy production point and demand point.

There are lead acid batteries, NaS batteries, supercapacitors, lithium secondary batteries and redox flwo batteries (RFB) as MW-class large capacity electric storage batteries.

The term secondary battery refers to a battery that can be recycled by repeating charging and discharging, not by a single use.

The redox flow cell is composed of an electrode, an electrolyte, an ion exchange membrane, and the like, and has the following advantages.

Because redox batteries store electricity in the electrolyte, they increase the stored power by increasing the electrolyte, not by increasing the cells. By separating the cells and the electrolyte, it is possible to store the charged electrolyte in a closed container Power can be stored at low cost over a long period of time. Because redox batteries do not require special manufacturing facilities for their manufacture, they can be manufactured from small (several watts) to large (tens of thousands of kilowatts).

Since the electrolytic solution uses a sulfuric acid solution containing both vanadium and anodic electrolytes, it does not generate heat or generate harmful gas even if the liquid is mixed. There is no fear of overcharging or overdischarging, and the risk of ignition or explosion There is no.

On the other hand, general batteries have a performance controversy on the scale of power density (storage amount per unit weight) at the time of portable (negative reflection), but in the case of batteries for large power storage used in fixed installation such as redox battery, It is a mistake to discuss performance at this point, and it is necessary to discuss how safe, reliable and low-cost power can be stored. In this sense, there is nothing to replace the redox battery in the reserve of large power.

The performance of such redox cells is characterized by their inherent characteristics such as equivalent resistance of the electrodes, distance between electrodes, specific surface area of the fibrous activated carbon, equivalent resistance of the diaphragm (resistance when the ions are permeated, And the characteristics of the electrolytic solution. In this case, the items related to the characteristics of the electrolytic solution will be described.

Since the redox battery is a type of cell in which oxidation and reduction are simultaneously performed in the anode and the cathode, there is no problem in operating even if the performance of the component described above is slightly worse. However, if the basic characteristics of the electrolyte are not satisfied, There is a problem in that it does not work at all.

Among the constituent elements of the battery, the requirements for the electrolytic solution in the case of the vanadium redox battery are a sulfuric acid solution containing vanadium salt as the anolyte solution and a sulfuric acid solution containing vanadium salt as the anode solution, And if each ion concentration is nearly equal, it can operate as a battery, but if there is an extreme concentration difference, there is a problem that it does not work properly.

Korean Patent No. 10-1049179 (redox flow battery including separator)

SUMMARY OF THE INVENTION The present invention has been made in order to solve the above-mentioned problems, and it is an object of the present invention to provide a method of continuously performing electrolysis using vanadium oxide sulfate as a starting material and, when the difference in oxidation reduction potential (ORP) to end the delivered in ^{V 2 +, V 3 +,} V 4 +, with the ion of the V ^{5 +} catholyte and anolyte to provide an electrolyte solution production apparatus and production method for VRB using electrolysis capable of producing a There is.

In order to achieve the above object, an electrolytic solution producing apparatus for VRB using electrolysis according to the present invention is characterized by comprising a cathode for primary electrolysis, a cathode for primary electrolysis, a cathode for primary electrolysis, A diaphragm for separating the primary electrolytic anode tank and the primary electrolytic anolyte, a sulfuric acid solution in which vanadium oxide sulfate is dissolved in the primary electrolytic anode tank and the primary electrolytic anode tank, A secondary electrolytic anode tank, a power supply for supplying power to the secondary electrolytic anode tank and the secondary battery electrolytic tank, a secondary electrolytic anode tank containing the secondary electrolytic anode tank, A separator for separating the anode and the anode from each other, and a separator for separating the anode and the cathode from each other, and a second cathode solution electrolyzed in the cathode compartment for the first electrolysis in the cathode compartment for the second electrolysis, And collecting functions A first bipolar plate, a first carbon felt electrode for causing an oxidation reaction and a reduction reaction of the third anolyte, a bipolar electrolytic space composed of a bipolar electrolytic solution flow frame, a second bipolar plate for performing a current collecting function, A second carbon felt electrode causing oxidation and reduction reactions, a negative electrode electrolytic space composed of a negative electrode electrolyte flow frame, an ion exchange membrane separating the anodic electrolytic space and the negative electrolytic space, a power supply unit supplying power to the cell, And a tertiary electrolytic apparatus including a resistor for inducing a discharge in the cell. The present invention also provides an apparatus for producing an electrolyte for VRB using electrolysis.

In the apparatus for producing an electrolyte for VRB using electrolysis of the present invention, a nitrogen supply device is connected to the primary electrolytic cell and the primary cell for electrolysis.

In the electrolytic solution producing apparatus for VRB using electrolysis according to the present invention, a nitrogen supply device is connected to the secondary electrolytic cathodes and the secondary electrolytic cathodes.

In the apparatus for producing an electrolyte for VRB using electrolysis according to the present invention, a pump for supplying and circulating a third catholyte obtained by electrolyzing the second catholyte at the (-) electrode in the catholyte electrolysis space, And a pump for supplying and circulating a third anolyte obtained by electrolyzing the second catholyte solution at the (+) electrode.

Further, in the apparatus for producing an electrolyte for VRB using electrolysis of the present invention, a pump capable of supplying and circulating a sulfuric acid solution in which vanadium oxide sulfate is dissolved is further included in the primary electrolysis catholyte and the primary electrolysis catholyte do.

Further, in the electrolytic solution producing apparatus for VRB using electrolysis of the present invention, the secondary electrolytic catholayer and the secondary electrolytic catholyte further include a pump capable of supplying and circulating the second catholyte.

In the apparatus for producing an electrolyte for VRB using electrolysis according to the present invention, a cathode electrolyte tank for storing a third anolyte obtained by electrolyzing the second catholyte at the (+) electrode, And a cathode electrolyte tank for storing a third cathode solution electrolyzed in the cathode, and a nitrogen supply device is connected to the cathode electrolyte tank and the cathode electrolyte tank, respectively.

In the electrolytic solution producing apparatus for VRB using electrolysis according to the present invention, the second catholyte solution contains V ^{3 +} .

Further, in the apparatus for producing an electrolyte for VRB using electrolysis of the present invention, it is preferable that the sulfuric acid solution in which the vanadium oxide vanadium is subjected to the primary electrolysis at the anode and the sulfuric acid solution in which the vanadium oxide vanadium The ORP difference is more than 1150mV.

In the electrolytic solution producing apparatus for VRB using electrolysis of the present invention, the power supply device of the primary electrolytic device variably supplies DC power to 1 to 10 V.

In the electrolytic solution producing apparatus for VRB using electrolysis of the present invention, the power supply unit of the secondary electrolytic apparatus supplies 1 to 10 V of direct current power.

In the apparatus for producing an electrolyte for VRB using electrolysis according to the present invention, when the third anolyte and the third anolyte are supplied to the third electrolysis apparatus, the ORP of the third anolyte is 800 to 850 mV, The ORP of the cathode solution is -400 to -300 mV.

In the apparatus for producing an electrolyte for VRB using electrolysis of the present invention, the third anolyte solution contains V ^{5 +} ions.

In the electrolytic solution producing apparatus for VRB using electrolysis of the present invention, the third catholyte solution contains V ^{2 +} ions.

In the apparatus for producing an electrolyte for VRB using electrolysis according to the present invention, the third electrolysis and the discharge reaction are terminated when the difference in ORP becomes 1300 to 1500 mV due to the electrolysis reaction and the discharge reaction in the third electrolysis apparatus .

A method for producing an electrolyte for VRB using electrolysis according to the present invention comprises: a step (S10) of electrolyzing a sulfuric acid solution in which vanadium oxide sulfate is dissolved in a primary electrolytic apparatus; and a step (S20) of performing secondary electrolysis of the obtained second catholyte obtained by electrolysis and a third anolyte and a third anolyte obtained respectively in the secondary electrolytic catholyte and the secondary electrolytic catholyte of the secondary electrolytic apparatus And discharging and electrolyzing (S30).

In the method for producing an electrolyte for VRB using electrolysis according to the present invention, the step (S30) of discharging and electrolyzing the third anolyte and the third anolyte is characterized in that ORP difference between the third anolyte and the third anolyte is Repeat this process until it reaches 1300 ~ 1500mV.

In the method for producing an electrolyte for VRB using electrolysis of the present invention, the power supplied in the step (S10) of electrolyzing by the primary electrolytic apparatus variably supplies DC power from 1 V to 10 V.

Further, in the electrolytic solution producing method for VRB according to the present invention, in the step (S10) of electrolyzing in the primary electrolytic apparatus, the sulfuric acid solution in which the primary electrolysis of vanadium oxide vanadium is dissolved in the anode and the The difference in ORP of the sulfuric acid solution in which the vanadium oxide sulfate subjected to the car electrolysis dissolves is over 1150 mV.

In the method for producing an electrolyte solution for VRB using electrolysis of the present invention, the second catholyte solution contains V ^{3 +} .

Further, in the method for producing an electrolyte for VRB using electrolysis of the present invention, the third anolyte which is the electrolyte of the (+) polarity obtained in the step (S20) of the second electrolysis includes VO ₂ ⁺ Lt; _{RTI ID} = 0.0 > VSO4. ≪ / RTI >

In the electrolytic solution for VRB using electrolysis according to the present invention, when the ORP of the first catholyte is -300 mV or less in the first electrolysis step (S10), the sulfuric acid solution in which vanadium oxide sulfate is dissolved is heated to 10 to 50 Ml.

In the electrolytic solution for VRB according to the present invention, the ORP of the electrolyte in the (+) electrode is 800 to 850 mV and the ORP of the electrolyte in the (-) electrode is The secondary electrolysis is terminated at -400 to -300 mV.

According to the apparatus for producing an electrolyte for VRB using electrolysis according to the present invention and the method for producing the same, it is possible to obtain V ²⁺ , V ³⁺ , V ⁴⁺ , V ⁵⁺ from a single precursor, vanadium oxide, purified from V ₂ O ₅ , It is possible to produce a high-purity anolyte and a catholyte solution.

When the electrolyte solution for VRB is made, high-purity anolyte and catholyte can be produced without requiring a secondary process for removing impurities because impurities are not generated. Therefore, the production of a high-efficiency electrolytic solution for a redox- It is possible.

1 is a schematic diagram showing a primary electrolytic apparatus according to the present invention.
2 is a schematic diagram showing a secondary electrolytic apparatus according to the present invention.
3 is a schematic diagram showing a configuration of a tertiary electrolytic apparatus according to the present invention.
4 is a schematic view showing a state in which electrolyte flows of a tertiary electrolytic apparatus according to the present invention are connected in series.
FIG. 5 is a schematic view showing a state in which electrolyte flows of the tertiary electrolytic apparatus according to the present invention are connected in parallel. FIG.
FIG. 6 is a schematic diagram showing a reaction occurring in an apparatus for producing an electrolyte for VRB using electrolysis according to the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, it should be understood that the following embodiments are provided so that those skilled in the art will be able to fully understand the present invention, and that various modifications may be made without departing from the scope of the present invention. It is not. Wherein like reference numerals refer to like elements throughout.

An electrolytic solution producing apparatus for VRB using electrolysis according to the present invention is characterized by comprising a cathode for primary electrolysis, a cathode for primary electrolysis, a cathode for cathode for electrolysis, a power supply for supplying power to the cathode for cathodic electrolysis, A primary electrolytic apparatus including a primary electrolytic catholyte and a primary electrolytic catholyte, a separator for separating the primary electrolytic catholyte and the primary electrolytic catholyte, a primary electrolytic catholyte and a sulfuric acid solution in which vanadium oxide is dissolved in the primary electrolytic catholyte, A secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly and a power supply device for supplying power to the secondary electrolytic cathodic assembly, a secondary electrolytic cathodic assembly and a secondary electrolytic cathodic assembly A secondary electrolytic apparatus including a secondary catholyte electrolytically decomposed in the primary electrolytic catholyte in the secondary electrolytic catholyte and the secondary catholyte in the secondary electrolytic catholyte, Bipolar plates, oxidation of the third anolyte A first carbon felt electrode for causing a reduction reaction with the first carbon felt electrode, a positive electrode electrolytic space formed by a positive electrode electrolyte flow frame, a second bipolar plate for performing a current collecting function, a second carbon felt electrode for causing oxidation reaction and reduction reaction of the third negative electrode liquid A negative electrode electrolytic space comprising a negative electrode electrolyte flow frame, an ion exchange membrane for separating the positive electrode electrolytic space and the negative electrode electrolytic space, a power supply for supplying power to the cell, and a resistor for inducing discharge in the cell A device for manufacturing an electrolyte solution for VRB using electrolysis, which comprises a secondary electrolytic device.

At this time, it is preferable that at least one of the primary electrolytic apparatus and the secondary electrolytic apparatus includes a nitrogen supply device. The reason why the nitrogen is supplied in this manner is that it is preferable that the electrolysis reaction occurring in each of the primary electrolytic apparatus and the secondary electrolytic apparatus proceeds in a reducing atmosphere in which nitrogen flows.

It is preferable that the above-mentioned primary electrolytic apparatus is provided with a pump so that a sulfuric acid solution in which vanadium oxide sulfate is dissolved in the cathode electrolysis cathodes and the cathode cathodes for the primary electrolysis can be supplied and circulated.

The secondary electrolytic apparatus described above is preferably provided with a pump so as to be able to supply and circulate the second catholyte to the secondary electrolytic catholyte and the secondary electrolytic catholyte.

Also, the above-mentioned third electrolytic apparatus is characterized in that the third catholyte solution electrolyzed in the (+) polarity of the second catholyte and the pump capable of supplying the third catholyte electrolyzed in the (-) pole of the second catholyte .

Although not shown, the cathode electrolyte tank storing the third anolyte solution electrolyzed at the (+) electrode of the second catholyte and the cathode electrolyte tank storing the third anolyte electrolyzed at the (-) electrode of the second catholyte It is preferable that it is separately provided.

A nitrogen supply device is connected to the positive electrode electrolyte tank and the negative electrode electrolyte tank, respectively, and it is preferable to proceed in a reducing atmosphere in which nitrogen flows.

1 is a schematic diagram showing a primary electrolytic apparatus according to the present invention.

Referring to FIG. 1, the primary electrolysis is performed in a reducing atmosphere in which nitrogen is supplied through a nitrogen supplier 30 in a closed state. Then, a sulfuric acid solution in which vanadium oxide is dissolved is supplied to the first electrolytic anode tank 110 and the first electrolytic anode tank 120. And circulating during the electrolysis using the pumps 12a and 12b. Here, the first anolyte (25) and the first anolyte (26) are sulfuric acid solutions in which vanadium oxide sulfate is dissolved.

The first anolyte (25) produces VO ₂ ⁺ through the reaction as shown in Formula (1). As can be seen from the formula (1), sulfuric acid is used as a solvent for electrolysis.

Then, the first catholyte solution 26 forms V ₂ (SO ₄ ) ₃ through a reaction similar to that of the general formula (2).

At this time, most of the first catholyte 26 after the first electrolysis is changed to V ₂ (SO ₄ ) ₃ , but also a small amount of vanadium oxide sulfate. On the other hand, the first anolyte (25) which has undergone the first electrolysis is oxidized with tetravalent vanadium ions to form a sulfate, along with the desorption of hydrogen. However, the amount of the first anolyte (25) Which contains a large amount of vanadium oxide sulfate. For this reason, the first anolyte (25) subjected to the first electrolysis is not used but the second anolyte (27) subjected to the first electrolysis is used.

The first-order depolarizer is regularized to 10 to 40 DEG C by a thermostat (not shown), and the first cathode solution 25 of the first electrolytic anode tank 110 and the first electrolytic cathode tank 120 Of the first anode liquid 26 is circulated at a rate of 1 liter per minute. The first-order decomposing device covers the lid (not shown) and flows nitrogen (N ₂ ) gas at a rate of 0.1 to 0.2 liter per minute.

The electrolysis method is a constant voltage electrolysis, and voltage setting is performed in three steps.

In the initial electrolysis, the voltage of the power supply 20 is set in the order of 1V, 3V, 5V, and the electrolysis is conducted until the supplied current reaches the limit current value of the electrolytic cell. After reaching the limit current value, the electrolysis mode is converted into the constant current and the electrolysis is continued, and the pH and ORP measurement are performed in parallel.

When the ORP of the first catholyte reaches -300 mV, a sulfuric acid solution in which vanadium oxide sulfate is dissolved is added to the first catholyte and the first electrolytic process is continued. Through this process, when the ORP difference between the sulfuric acid solution in which the primary electrolysis of vanadium oxide vanadium is dissolved in the anode and the sulfuric acid solution in which the vanadium oxide vanadium dissolved in the primary electrolysis in the cathode is more than 1150 mV, the primary electrolysis is terminated do.

2 is a schematic diagram showing a secondary electrolytic apparatus according to the present invention.

2, the first electrolytically-decomposed second catholyte solution 27 is supplied to the second anolyte 210, the second anolyte 27 of the second electrolytic aeration tank 220, 2 is used as the catholyte (27).

It is preferable that the electrolysis mode is a constant voltage electrolysis mode and the voltage setting is a electrolysis mode at a fixed voltage of 1 to 10V.

The ORP and the electrolytic current of the second anolyte 27 and the second anolyte 27 are measured in the same manner as in the first electrolysis, and graphs are made to verify the transition of the electrolysis state.

At this time, the voltage rising speed of the second catholyte 27 of the secondary electrolytic cell 210 rapidly progresses, and the voltage lowering speed of the second catholyte 27 of the secondary electrolytic cell 220 is slow It proceeds.

When the voltage rising rate of the secondary electrolytic anode tank 210 is stalled, a predetermined amount of vanadium oxide sulfate or VO ₂ ⁺ after completion of the first electrolysis is added to the secondary electrolytic anode tank 220 and titrated. The amount of VO ₂ ⁺ added in the predetermined amount is preferably 0.1 to 20 ml.

2, the end point of the primary electrolysis is V solution containing ^{5 +} ion (the "third anolyte" refers to the) solution containing (29) ORP is a 800 ~ 850mV, the V ^{2 +} ions (the "second 3 catholyte ') is the point where the ORP of (28) becomes -400 to -300 mV.

At this time, the color of the third anolyte (29) becomes orange and the color of the third anolyte (28) becomes purple. As you know, the positive charge of vanadium is orange when it is 5, and it becomes purple when positive charge is 2.

Formula 3 is a formula showing that a solution 28 containing V ^{5 +} is formed through the secondary electrolytic apparatus according to the present invention.

Formula 4 is a formula showing that a solution 29 containing V ^{2 +} is formed through the secondary electrolytic apparatus according to the present invention.

3 is a schematic diagram showing a configuration of a tertiary electrolytic apparatus according to the present invention.

3, the tertiary electrolytic apparatus includes a first bipolar plate 302 that performs a current collecting function, a first carbon felt electrode 304 that causes an oxidation reaction and a reduction reaction of the third anolyte, A second bipolar plate 307 which performs a current collecting function, a second carbon felt electrode 308 which causes an oxidation reaction and a reduction reaction of the third catholyte, a cathode electrolytic solution flow A cathode electrolysis space 320 constituted by a frame 307, an ion exchange membrane 305 separating the anode electrolysis space and the anode electrolysis space, a power supply unit 20 supplying power to the cell 300, There is provided an apparatus for producing an electrolyte solution for VRB using electrolysis including a tertiary electrolytic apparatus including a resistor (40) for inducing a discharge in a cell (300).

3, the third electrolytic decomposition step includes the steps of putting the third anolyte solution 29 and the third anolyte solution 28 into the anode electrolysis space 310 and the cathode electrolysis space 320, And repeating the discharge to increase the efficiency of the battery.

In the configuration of FIG. 3, the first bipolar plate 302 and the second bipolar plate 307 separate each cell 300 to prevent the third anolyte 29 and the third anolyte 28 from mixing. The first carbon felt electrode 304 and the second carbon felt electrode 309 are connected to the (+) and (-) poles, respectively, and serve to facilitate control and flow of the flowing current.

The first carbon felt electrode 304 and the second carbon felt electrode 309 are materials in which the constituent material is a carbon fiber and exhibits characteristics different from bulk carbon or graphite. The microstructure of the first carbon felt electrode 304 and the second carbon felt electrode 309 vary greatly depending on the precursor and the manufacturing conditions.

As a starting material most commonly used in the production of the carbon felt which is a constituent material of the first carbon felt electrode 304 and the second carbon felt electrode 309, there are rayon, PAN (polyacrylonitrile), pitch Lt; / RTI >

The carbon felt, which is a constituent material of the first carbon felt electrode 304 and the second carbon felt electrode 309, expands the surface area of the electrode through chemical, electrochemical and thermal activation, and when oxygen functional groups are introduced on the surface of the carbon felt, And thus causes oxidation / reduction reaction in the electrolyte.

And the anode electrolyte flow frame 303 is supplied with the third anolyte 29, which is the anode electrolyte. Further, the cathode electrolyte flow frame 308 is supplied with the third cathode liquid 28 which is the cathode electrolyte.

4 is a schematic view showing a state in which electrolyte flows of a tertiary electrolytic apparatus according to the present invention are connected in series.

Referring to FIG. 4, electrolysis and discharge are simultaneously performed through the tertiary electrolytic apparatus.

In FIG. 4, it is preferable that the DC power is supplied through the power supply unit 20 during the electrolysis, and the discharge is performed through the resistor 40 during the discharge.

Formulas 5 and 6 are chemical formulas showing chemical reactions when the third anolyte solution 29 and the third anolyte solution 28 are electrolyzed or discharged.

It is preferable that the input means for discharging and electrolyzing are separately provided. In other words, it is preferable that a DC power supply device is provided for electrolysis and a discharge means is provided for discharging. In the electrolytic apparatus for electrolytic solution for VRB according to the present invention and the method for producing electrolytic solution according to the present invention, it is preferable that a resistor 40 is provided as a discharging apparatus.

In FIG. 4, electrolyte flows are connected in series in a cell 300 that includes a cathode electrolytic space 310 and a cathode electrolytic space 320, respectively. A plurality of cells 300 including the anode electrolysis space 310 and the cathode electrolysis space 320 may be provided. However, the power supply 20 may be connected or the resistor 40 may be connected depending on whether the discharge mode or the electrolysis mode is selected.

At this time, it is preferable that the discharge current has a predetermined current value when discharging. Specifically, the predetermined current value is preferably 1 to 10A.

When performing electrolysis, it is preferable that the power supply device 20 is a direct current power supply means, and the supply voltage is preferably 1 to 10V.

FIG. 5 is a schematic view showing a state in which electrolyte flows of the tertiary electrolytic apparatus according to the present invention are connected in parallel. FIG.

Referring to FIG. 5, the constituent units of the cell 300 are connected in series to the anode electrolysis space 310 and the cathode electrolysis space 320.

The reason why the third electrolysis process proceeds after the second electrolysis is that the electrolytic solution of V ^{2 +} produced in the ^second electrolysis process and the electrolyte of V ^{5 +} are not completely formed. The reason why the ions of V ^{2 +} and V ^{5 +} are not generated at 100% is because the charge state of the vanadium ion is in a state of 2-valence, 5-valence is 3 and valium is more stable.

The V ^{2 +} ions (the third anolyte) and the V ^{5 +} ions (the third anolyte) obtained through electrolysis or charging are generated until the charging is completed.

When the ten thousand and one V ^{4 +} ions are present in the anolyte 3, V ^{4 +} ions is to form the V ^{+ 5} and the electric double layer is present in the ion mass. When the V ^{4 +} and V ^{5 +} ions remain in the ion mass, some of the electrical energy is used to destroy the electrical double layer during charging of the cell. Therefore, even if the battery is subjected to the 100% charging process, there is a problem that the energy loss is 30% in the discharging process and the discharging is performed only 70%.

However, when electrolysis and discharge are performed through the third electrolysis process, the electric double layer is destroyed in advance, and a high purity solution composed entirely of V ^{5 +} ions can be obtained. When such a high purity electrolyte solution is obtained, the efficiency of the battery increases to 95%.

The increase in the efficiency of the battery can be confirmed by confirming the ORP. When the ORP difference between the positive (+) and negative (-) poles reaches 1300 to 1500 mV, the third electrolysis and the discharge reaction are terminated.

Hereinafter, a method for producing an electrolytic solution for VRB using such electrolysis will be described.

A method for producing an electrolyte for VRB using electrolysis according to the present invention comprises: a step (S10) of electrolyzing a sulfuric acid solution in which vanadium oxide sulfate is dissolved in a primary electrolytic apparatus; and a step (S20) of performing secondary electrolysis of the obtained second catholyte obtained by electrolysis and a third anolyte and a third anolyte obtained respectively in the secondary electrolytic catholyte and the secondary electrolytic catholyte of the secondary electrolytic apparatus And discharging the third anolyte and the third anolyte to electrolyze the obtained result (S30).

The step (S30) of discharging and electrolyzing the third anolyte and the third anolyte is repeated until the ORP difference between the third anolyte and the third anolyte becomes 1300 to 1500 mV.

FIG. 6 is a diagram illustrating chemical reactions occurring in the preparation of an electrolyte solution for VRB using electrolysis according to the present invention in a time sequence.

Referring to FIG. 6, in the case of the present invention, vanadium oxide sulfate is used as a precursor for preparing an electrolyte of a vanadium redox battery.

The thus obtained sulfuric acid solution in which vanadium oxide vanadium is dissolved is electrolyzed in a primary electrolysis apparatus (S10). Formulas (1) and (2) are chemical formulas showing the reactions occurring in the primary electrolytic apparatus.

As described above, in the first anolyte solution 25, the tetravalent vanadium ions are oxidized to form a sulfate by dissociation of hydrogen, but the amount thereof is not sufficient due to the liberation of hydrogen, and sulfuric acid oxidation It contains a large amount of vanadium.

Such a primary electrolysis uses a constant voltage electrolysis method, which is preferably maintained at 1 V for the initial 2 hours, and 3 hours at 3 V for the subsequent electrolysis. Finally, the final voltage is maintained at 5V and constant voltage electrolysis continues until the current reaches the limit current value. After reaching the limit current, proceed to constant current electrolysis and periodically measure pH and ORP. The limiting current value is calculated as the product of the area of contact of the sulfuric acid solution used for electrolysis with the diaphragm 15 and the current value of the diaphragm 15, and electrolysis is performed until the limit current value is reached.

At this time, when the ORP of the first anode liquid 26 reaches -300 mV, it is preferable to further add about 10 to 50 ml of the sulfuric acid solution in which vanadium oxide sulfate is dissolved.

It is preferable that the first electrolytic reaction proceeds until the potential difference between the first anolyte 25 and the first catholyte 26 reaches 1150 mV (S15).

The second catholyte (27) having undergone the reaction of the formula (2) is introduced into the secondary electrolytic apparatus (S20). Thus, in the secondary electrolytic apparatus, the +3 valence vanadium ion participates in the electrolysis, as can be seen from the formulas (3) and (4).

In the secondary anode tank 210, an oxidation reaction occurs while supplying electrons e ^- to the anode (+). In the secondary cathode tank 220, electrons (e ^- ) are supplied from the cathode It happens. As a result, the second anolyte 27 becomes a solution 29 containing vanadium pentavalent ions, and the second catholyte 27 becomes a solution 28 containing vanadium divalent ions.

At this time, it is preferable that the power supply apparatus 20 is a DC power supply having a voltage of 1 to 10V.

It is preferable that the ORP of the third anolyte (29) containing V ^{5 +} ions is 800 to 850 mV (S24) at the time of completion of the second electrolysis with respect to the second anolyte (27).

It is preferable that the ORP of the third anode liquid 28 containing V ^{2 +} ions is -400 to -300 mV (S26) at the time of completion of the second electrolysis with respect to the second anode liquid 27.

However, when passing through the secondary electrolytic unit, the concentration of V ^{2 +} ions can be lowered to a desired level, but it is difficult to ensure the concentration of V ^{5 +} ions. In order to balance the charge balance (balance) of both polar ions and the situation, the tertiary electrolysis is performed (S30). The third electrolysis process is aimed at destroying the electric double layer generated by the V ^{4 +} and V ^{5 +} ions in addition to balancing the charge of both polar ions.

In the case of the vanadium redox flow cell claimed in the present invention, when such a high purity electrolytic solution is obtained, the efficiency of the battery can be increased up to 95%.

At this time, the voltage difference between the electrolytic solution of the finally calculated V ^{5 +} ion and the electrolytic solution of the V ^{2 +} ion is preferably 1300 mV to 1500 mV.

At this time, the discharge current is preferably 1 to 10A.

Particularly, since the ion exchange membrane 305 is provided between the solution containing the V ^{5 +} ion and the solution containing the V ^{2 +} ion, the solution 29 containing the V ^{5 +} ion is dissolved in the solution containing the V ^{2 +} (28).

In this way, the third electrolysis is performed simultaneously with the discharge, and it is preferable that the apparatus is equipped with the devices 20, 40 capable of electrolysis and discharge so that the electric double layer is destroyed by discharging after the charging is completed .

As mentioned above, although preferred embodiment of this invention was described in detail, this invention is not limited to the said embodiment, A various deformation | transformation by a person of ordinary skill in the art within the scope of the technical idea of this invention is carried out. This is possible.

15: diaphragm 20: power supply
25: First Anolyte 26: First Anolyte
27: Second negative electrode liquid 28: Third negative electrode liquid
29: Third anolyte 30: Nitrogen supply device

Claims (22)

A first electrolytic cell, a first electrolytic cell, a first electrolytic cell, a first electrolytic cell, a first electrolytic cell, a first electrolytic cell, and a first electrolytic cell, A primary electrolytic apparatus comprising a sulfuric acid solution in which vanadium oxide is dissolved in each of the primary electrolysis cathodes and the primary electrolysis cathodes;
A secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly, a secondary electrolytic cathode assembly and a power supply device for supplying power to the secondary electrolytic cathodic assembly, a secondary electrolytic cathodic assembly and a secondary electrolytic cathodic assembly A secondary electrolytic apparatus including a secondary catholyte electrolytically decomposed in the primary electrolytic catholysis bath in each of the secondary electrolytic catholyte and the secondary electrolytic catholyte; And
A first bipolar plate performing a current collecting function, a first carbon felt electrode causing oxidation reaction and a reduction reaction of a third anolyte, a bipolar electrolytic space composed of a bipolar electrolyte flow frame, a second bipolar plate performing a current collecting function, A second carbon felt electrode for causing an oxidation reaction and a reduction reaction of the catholyte; a cathode electrolysis space constituted of a cathode electrolyte flow frame; an ion exchange membrane for separating the anode electrolysis space and the anode electrolysis space; A tertiary electrolytic apparatus including a power supply and a resistor for inducing a discharge in the cell;
And an electrolytic solution for electrolytic solution. The method of claim 1,
And the nitrogen supply device is connected to the primary electrolytic cathode set and the primary electrolytic solution cathode set. The method of claim 1,
And a nitrogen supply device is connected to the secondary electrolytic catholyte and the secondary electrolytic catholyte. The method of claim 1,
A negative electrode electrolytic space provided with a pump for supplying and circulating a third negative electrode liquid obtained by electrolyzing the second negative electrode liquid at the (-) electrode, and a second electrolytic cell for electrolyzing the second negative electrode liquid at the positive electrode in the positive electrode electrolytic space 3. The electrolytic solution producing apparatus for VRB according to claim 1, further comprising a pump for supplying and circulating the anolyte. The method of claim 1,
Further comprising a pump capable of supplying and circulating a sulfuric acid solution in which vanadium oxide sulfate is dissolved in the primary electrolytic anode tank and the primary electrolytic anode tank. The method of claim 1,
Further comprising a pump capable of supplying and circulating the second catholyte to the secondary electrolytic anode tank and the secondary electrolytic catholyte tank. The method according to claim 1 or 4,
A negative electrode electrolytic tank storing a third anolyte obtained by electrolyzing the second negative electrode liquid at the positive electrode and a third anolyte obtained by electrolyzing the second anolyte at the negative electrode, Including,
And a nitrogen supply device is connected to the positive electrode electrolyte tank and the negative electrode electrolyte tank, respectively. 7. The method according to claim 1 or 6,
And the second catholyte solution includes V ₂ (SO ₄ ) ₃ . 7. The method according to claim 1 or 6,
When the second catholyte is supplied to the secondary electrolytic apparatus, the ORP difference between the sulfuric acid solution in which the primary electrolysis of vanadium oxide vanadium is dissolved in the anode and the sulfuric acid solution in which the primary electrolysis in the cathode is dissolved in the vanadium sulfate vanadium Is at least 1150 mV. The method of claim 1,
Wherein the power supply device of the primary electrolytic device variably supplies DC power from 1 to 10 V. The apparatus for producing electrolytic solution for VRB according to claim 1, The method of claim 1,
Wherein the power supply unit of the secondary electrolytic apparatus supplies 1 to 10 V of a direct current power source. The method of claim 1,
Wherein the third anolyte solution contains V ^{5 +} ions. The method of claim 1,
Wherein the third catholyte solution contains V ^{2 +} ions. The method of claim 1,
Wherein an ORP of the third anolyte is 800 to 850 mV and an ORP of the third anolyte is -400 to -300 mV when the third anolyte and the third anolyte are supplied to the tertiary electrolytic apparatus. An apparatus for producing electrolyte for VRB using decomposition. The method of claim 1,
Wherein the third electrolysis and the discharge reaction are terminated when the difference between the ORP of the third anolyte and the third anolyte becomes 1300 to 1500 mV in the electrolysis reaction and the discharge reaction in the tertiary electrolysis apparatus, For producing an electrolytic solution for VRB. (S10) electrolyzing the sulfuric acid solution in which the vanadium oxide sulfate is dissolved in the primary electrolytic apparatus;
A step (S20) of secondary electrolysis of the second catholyte obtained in the first electrolysis step; And
And discharging and electrolyzing the third anolyte and the third anolyte obtained in the second electrolysis process (S30). 17. The method of claim 16,
(S30) of discharging and electrolyzing the third anolyte and the third anolyte are repeatedly performed. 18. The method according to claim 16 or 17,
Wherein the power supplied in the step of electrolyzing by the primary electrolytic device is variably supplied with DC power from 1V to 10V. 18. The method according to claim 16 or 17,
In the step (S10) of electrolyzing in the primary electrolytic apparatus, the ORP difference between the sulfuric acid solution in which the primary electrolysis of vanadium oxide vanadium is dissolved in the anode and the sulfuric acid solution in which the primary electrolysis in the cathode is dissolved in the sulfuric acid vanadium oxide Is terminated at < RTI ID = 0.0 > 1150mV < / RTI > or higher. 18. The method according to claim 16 or 17,
Wherein the second catholyte solution comprises V ₂ (SO ₄ ) ₃ . 18. The method according to claim 16 or 17,
The third anolyte which is the electrolyte of the (+) polarity obtained in the second electrolysis step contains VO ₂ ⁺ and the third anolyte which is the electrolyte of the (-) electrode contains V ₂ (SO ₄ ) ₃ A method for producing an electrolytic solution for VRB using electrolysis. 18. The method according to claim 16 or 17,
Wherein the secondary electrolysis is ended when the ORP of the electrolyte of the (+) electrode is 800 to 850 mV and the ORP of the electrolyte of the (-) electrode is -400 to -300 mV in the secondary electrolysis step. (Method for manufacturing electrolytic solution for VRB using decomposition).

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