Apparatus and method for continuous processing of electrolyte solution containing vanadium ions

Abstract

The present invention relates to an apparatus and a method for processing of an electrolyte solution containing vanadium ions, the apparatus comprising: a first electrolyte solution storage part for storing an electrolyte solution containing vanadium ions; a first impurity removal part, which is connected to the electrolyte solution storage part and primarily removes, by means of a charge reaction, impurities from the electrolyte solution containing vanadium ions; a second impurity removal part, which reacts the electrolyte solution containing vanadium ions, that has passed through the first impurity removal part, with an extractant so as to secondarily remove impurities; and a second electrolyte solution storage part for recovering and storing the electrolyte solution containing vanadium ions, that has passed through the second impurity removal part, wherein the temperature required for the second impurity removal part is provided by the first impurity removal part.

Description

Continuous treatment device and method for electrolyte containing vanadium ions

[0001] The present invention relates to a technology for treating impurities in an electrolyte containing vanadium ions. More specifically, the present invention relates to a device and method for continuously removing impurities from an electrolyte containing vanadium ions using electrochemical reactions and extraction reactions.

[0002] Vanadium ion batteries (VIBs) and vanadium redox flow batteries (VRFBs) utilize electrolytes containing vanadium ions. Electrolytes containing vanadium ions are aqueous, so they offer high safety against explosions and other issues when applied to secondary batteries, as well as the added benefit of extending battery life. This has led to their continued use until recently. Furthermore, electrolytes containing vanadium ions have the longest lifespan among oxidation-reduction secondary batteries, are advantageous for increasing capacity, and can be separated and reused through the electrochemical reaction of charge and discharge in secondary batteries, resulting in cost savings.

[0003] The electrolyte containing vanadium ions used in the oxidation electrode section (also called the anode section) and the reduction electrode section (also called the cathode section) requires vanadium ions with an oxidation number of 4+ for the oxidation electrode section and 3+ for the reduction electrode section, respectively, based on a fully discharged state, and vanadium ions with an oxidation number of 5+ for the oxidation electrode section and 2+ for the reduction electrode section, based on a fully charged state. The charge / discharge reaction occurs as the oxidation number of the vanadium active material changes, and in order for the electrochemical reversible reaction to occur, it is important to manufacture the electrolyte of the oxidation electrode section and the reduction electrode section so that the oxidation numbers of the vanadium ions are matched.

[0004] In general, as a vanadium ion-containing electrolyte, an electrolyte with a vanadium oxidation number of 3.5 (3.5+) that can be commonly used for the electrolyte supplied to the reduction electrode section and the electrolyte supplied to the oxidation electrode section has been used.

[0005] Meanwhile, if impurities exceed a certain level in an electrolyte containing vanadium ions, side reactions can occur, leading to problems such as reduced performance and lifespan. In particular, batteries using electrolytes containing vanadium ions undergo repeated charging and discharging, which can lead to the continuous accumulation of damage caused by side reactions, potentially leading to fatal problems such as battery failure.

[0006] Furthermore, if a certain level of impurities are present in the vanadium-ion-containing electrolyte, pressure will be generated during the electroreduction process at the reduction electrode. This pressure generation can degrade the life characteristics. Compared to vanadium redox flow batteries, vanadium-ion batteries have a relatively small volume, making it difficult to buffer the pressure generation, making this pressure generation a greater problem in vanadium-ion batteries.

[0007] Among the elements present in the electrolyte containing vanadium ions, impurities such as metals, especially transition elements such as Cr, Mn, Fe, Ni, Cu, Zn, Mo, Pd, Cd, and Pt, are factors that cause hydrogen generation.

[0008] Therefore, a technology to remove metal impurities such as transition elements in an electrolyte containing vanadium ions is required.

[0009] To remove metal impurities, methods utilizing extractants are primarily used. Figure 1 schematically illustrates a device for extracting and removing metal impurities using a typical extractant.

[0010] Referring to Fig. 1, a vanadium-containing electrolyte having an oxidation number of 3.5 is continuously supplied from an electrolyte storage unit (101) in which a vanadium-containing electrolyte is stored to an extraction device (110) including an organic phase including kerosene and an extractant. The extraction device (110) includes an organic phase (112), a heating device (115) for providing a reaction temperature, and a stirrer (116) for even mixing. As the vanadium-containing electrolyte passes through the organic phase, impurities contained in the vanadium-containing electrolyte are transferred to the organic phase to form a treated vanadium-containing electrolyte (114). The vanadium-containing electrolyte from which impurities have been removed is recovered to the electrolyte storage unit (102).

[0011] At this time, the reaction temperature for removing impurities using an extractant is 40°C or higher, and a heating device (115) is essential for this.

[0012] The problem to be solved by the present invention is to provide a continuous treatment device for a vanadium ion electrolyte capable of effectively removing impurities from a vanadium ion-containing electrolyte.

[0013] The problem to be solved by the present invention is to provide a method for continuously removing impurities from a vanadium ion electrolyte using the above-described device for treating an electrolyte containing vanadium ions.

[0014] The objects of the present invention are not limited to the purposes mentioned above, and other purposes not mentioned will be clearly understood by those skilled in the art from the description below.

[0015] According to one embodiment of the present invention for solving the above problem, a device for processing a vanadium ion-containing electrolyte comprises: a first electrolyte storage unit for storing a vanadium ion-containing electrolyte; a first impurity removal unit connected to the electrolyte storage unit and performing a charging reaction on the vanadium ion-containing electrolyte to primarily remove impurities; a second impurity removal unit for secondarily removing impurities by reacting the vanadium ion-containing electrolyte passing through the first impurity removal unit with an extractant; and a second electrolyte storage unit for recovering and storing the vanadium ion-containing electrolyte passing through the second impurity removal unit.

[0016] The temperature required for the second impurity removal unit can be provided from the first impurity removal unit.

[0017] The first impurity removal unit includes an oxidation electrode unit and a reduction electrode unit, and the vanadium ion-containing electrolyte is separately supplied to the oxidation electrode unit and the reduction electrode unit, and the vanadium ion-containing electrolyte that has passed through the oxidation electrode unit and the vanadium ion-containing electrolyte that has passed through the reduction electrode unit can be combined.

[0018] The above vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.5, the vanadium ion-containing electrolyte passing through the reduction electrode unit has a vanadium ion oxidation number of 2 to 3, the vanadium ion-containing electrolyte passing through the oxidation electrode unit has a vanadium ion oxidation number of 4 to 5, and the combined vanadium ion-containing electrolyte may have a vanadium ion oxidation number of +3.5.

[0019] The temperature of the above-mentioned combined vanadium ion-containing electrolyte may be 30 to 60°C.

[0020] The second impurity removal unit may include an organic layer containing kerosene and an extractant.

[0021] According to one embodiment of the present invention for solving the above problem, a method for treating a vanadium ion-containing electrolyte comprises the steps of: separately supplying a vanadium ion-containing electrolyte to an oxidation electrode section and a reduction electrode section of a charging cell; performing an oxidation-reduction reaction on the vanadium ion-containing electrolyte in the charging cell to first remove impurities contained in the vanadium ion-containing electrolyte, and then mixing the vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section; reacting the mixed vanadium ion-containing electrolyte with an extractant to secondarily remove impurities contained in the vanadium ion-containing electrolyte; and recovering the vanadium ion-containing electrolyte from which the impurities have been removed.

[0022] By mixing the vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section, the temperature of the mixed vanadium ion-containing electrolyte can rise to 30 to 60°C.

[0023] In the second step of removing the above impurities, the temperature of the electrolyte containing vanadium ions of 30 to 60°C can be used as the reaction temperature.

[0024] The above vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.5, the vanadium ion-containing electrolyte passing through the reduction electrode unit has a vanadium ion oxidation number of 2 to 3, the vanadium ion-containing electrolyte passing through the oxidation electrode unit has a vanadium ion oxidation number of 4 to 5, and the combined vanadium ion-containing electrolyte may have a vanadium ion oxidation number of +3.5.

[0025] The second impurity removal unit includes an organic layer containing kerosene and an extractant, and as the vanadium ion-containing electrolyte passes through the organic layer, impurities contained in the vanadium ion-containing electrolyte can move to the organic layer.

[0026] The above extractant may be selected from at least one phosphoric acid extractant such as PC88A (2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester), TOPO (trioctylphosphine oxide), TBP (tributyl phosphate), DBP (dibutyl phosphate), HDEHP (Bis(2-ethylhexyl) hydrogen phosphate) and an amine extractant such as Alamine336.

[0027] According to the apparatus and method for continuous treatment of a vanadium ion-containing electrolyte according to the present invention, electrochemical impurity removal and impurity removal using an extractant can be continuously performed.

[0028] In particular, in the case of the present invention, by utilizing the elevated temperature generated during the electrolyte mixing process after electrochemical impurity removal in a charging cell as the reaction temperature for impurity removal using an extractant, impurities can be removed with high efficiency from an electrolyte containing vanadium ions without a separate heating device.

[0029] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

[0030] Figure 1 schematically illustrates a device for removing metal impurities using a general extractant.

[0031] Figure 2 schematically illustrates a continuous treatment device for a vanadium ion-containing electrolyte according to an embodiment of the present invention.

[0032] Figure 3 schematically illustrates the treatment process of a vanadium ion-containing electrolyte in a charging cell.

[0033] Figure 4 schematically illustrates a method for continuously processing a vanadium ion-containing electrolyte according to an embodiment of the present invention.

[0034] Figure 5 shows an example of a device capable of measuring the pressure of a cell.

[0035] Figure 6 shows the pressure measurement results of the examples and comparative examples.

[0036] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below and may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0037] Throughout this specification, unless otherwise specifically stated, each component may be singular or plural.

[0038] In interpreting the components in this specification, even if there is no separate explicit description, it is interpreted to include the range of error.

[0039] When it is described herein that any component is “connected,” “coupled,” or “connected” to another component, it should be understood that the components may be directly connected or connected to one another, but that other components may also be “interposed” between the components, or that each component may be “connected,” “coupled,” or “connected” through another component.

[0040] In this specification, when the terms "includes," "has," "consists of," "arranges," "provides," etc. are used for components, other parts may be added unless "only" is used.

[0041] Unless otherwise specified in this specification, any reference to a unit is interpreted to mean “weight.”

[0042] In this specification, unless otherwise specifically stated, “vanadium ion-containing electrolyte” is interpreted to refer to the same thing as “vanadium ion electrolyte,” “electrolyte using (utilizing) vanadium ions,” “electrolyte containing vanadium ions,” “vanadium electrolyte,” “electrolyte containing vanadium active material,” etc.

[0043] In this specification, the oxidation number of the vanadium ion of the vanadium ion electrolyte may be the oxidation number of the electrolyte itself at the time of manufacture or supply, or the average value of the oxidation number of the vanadium ion of the electrolyte supplied to the positive and negative electrodes, and may represent the average value of the oxidation number of the vanadium ion of the positive and negative electrolytes when the secondary battery is operated by charging and discharging.

[0044] In this specification, the reduction electrode part is an electrode where the oxidation number of vanadium ions decreases as a reduction reaction occurs, and may be referred to as a cathode part. In this specification, the oxidation electrode part is an electrode where the oxidation number of vanadium ions increases as an oxidation reaction occurs, and may be referred to as an anode part.

[0045] Figure 2 schematically illustrates a continuous treatment device for a vanadium ion-containing electrolyte according to an embodiment of the present invention.

[0046] Referring to FIG. 2, the continuous treatment device for a vanadium ion-containing electrolyte according to the present invention includes a first electrolyte storage unit (201), a first impurity removal unit (210), a second impurity removal unit (220), and a second electrolyte storage unit (202). Characteristically, in the case of the present invention, the temperature required for the second impurity removal unit can be provided in the first impurity removal unit (210).

[0047] The first electrolyte storage unit (201) stores an electrolyte containing vanadium ions having a predetermined oxidation number.

[0048] The first impurity removal unit (210) is connected to the electrolyte storage unit (201) and performs a charging reaction of the electrolyte containing vanadium ions to primarily remove impurities.

[0049] Specifically, the first impurity removal unit (210) is a charging cell, which includes an oxidation electrode unit and a reduction electrode unit with a separator between them.

[0050] In the first impurity removal unit (210), metal impurities are removed using an electrochemical method. This utilizes the principle that when the oxidation number of vanadium ions in the electrolyte in the charging cell is lower than the precipitation oxidation number of the metal impurity (e.g., 3), the metal impurity is precipitated (adsorbed) from the electrolyte solution to the electrode surface. That is, when an electrolyte containing vanadium and metal impurities undergoes a reduction reaction in the charging cell, the oxidation number of the vanadium ion is lowered from, for example, 3.5 to 2, and the metal impurity is precipitated, i.e., adsorbed, on the electrode. By this principle, metal impurities are removed from the vanadium-containing electrolyte, and the concentration of metal impurities in the vanadium-containing electrolyte can be lowered.

[0051] The vanadium ion-containing electrolyte is separately supplied to the oxidation electrode section and the reduction electrode section of the first impurity removal unit (210). The vanadium ion-containing electrolyte that has passed through the oxidation electrode section and the vanadium ion-containing electrolyte that has passed through the reduction electrode section are mixed / merged again.

[0052] Figure 3 schematically illustrates the treatment process of a vanadium ion-containing electrolyte in a charging cell.

[0053] Referring to FIG. 3, the vanadium ion-containing electrolyte supplied from the first electrolyte storage unit (201) may have a vanadium ion oxidation number of +3.5. Here, the oxidation number of 3.5 may mean an oxidation number of exactly 3.5, but may also mean an oxidation number within a range of about 3.4 to 3.6. The vanadium electrolyte contains vanadium ions and an acidic solution. The vanadium ions may be supplied by vanadium oxide, and may include, for example, one or more selected from the group consisting of V2O5, VOSO4, V2O3, NH4VO3, and V2O4, but is not necessarily limited thereto, and may be selected according to electrolyte production conditions, production target amount, etc. The acidic solution may include one or more selected from the group consisting of sulfuric acid, hydrochloric acid, nitric acid, and phosphoric acid, but, for example, a sulfuric acid solution may be used. The concentration of the acidic solution may be, for example, 0.1 M to 10 M, for example, 1 M to 8 M, for example, 2 M to 5 M, but is not necessarily limited thereto, and may be appropriately adjusted depending on the type of acidic solution selected, etc. The concentration of vanadium ions in the electrolyte containing vanadium may be, for example, 1.5 M to 3.7 M.

[0054] The vanadium ion-containing electrolyte passing through the reduction electrode section of the first impurity removal section (210) has a vanadium ion oxidation number of 2 to 3 that has been lowered by the reduction reaction, and the vanadium ion-containing electrolyte passing through the oxidation electrode section can have a vanadium ion oxidation number of 4 to 5 that has been increased by the oxidation reaction. The vanadium ion-containing electrolyte passing through the reduction electrode section and the vanadium ion-containing electrolyte passing through the oxidation electrode section are combined, so that the vanadium ion-containing electrolyte subjected to the first impurity removal treatment can have a vanadium ion oxidation number of +3.5.

[0055] At this time, the temperature of the electrolyte containing the merged vanadium ions can rise to 30 to 60°C. This can be seen as a portion of the approximately 27W of electrical energy applied to the charging cell being converted into thermal energy.

[0056] The second impurity removal unit (220) removes impurities for a second time by reacting the vanadium ion-containing electrolyte that has passed through the first impurity removal unit with an extractant.

[0057] The second impurity removal unit (220) includes an organic phase (222) and a stirrer (226) for even mixing. As the vanadium-containing electrolyte passes through the organic phase (222), impurities contained in the vanadium-containing electrolyte move to the organic phase (222), and the impurities are extracted and removed using an extractant.

[0058] In the second impurity removal unit (220), kerosene can be used as a representative material for forming an organic phase together with the extractant, but is not necessarily limited thereto.

[0059] The second electrolyte storage unit (202) recovers and stores the vanadium ion-containing electrolyte (224) that has passed through the second impurity removal unit. The second electrolyte storage unit (202) may be the same as the first electrolyte storage unit (201), or may be different from the first electrolyte storage unit (201), i.e., separate.

[0060] The type of impurity removed in the first impurity removal unit (charging cell) (210) can be determined according to the voltage, current, etc. applied to the charging cell, and the type of impurity removed in the second impurity removal unit (extraction device) (220) can be determined according to the type of extractant, the temperature of the extraction device, etc. In general, impurities such as Ni, Cu, Ag, Au, Ru, Pd, Rh, Sb, Te, Os, Ir, Pt, etc. can be removed in the charging cell, and Pd, Ag, Au, etc. can be removed in the extraction device.

[0061] The same impurity can be removed in the first impurity removal unit (210) and the second impurity removal unit (220). In this case, since specific impurities are sequentially removed in the first impurity removal unit and the second impurity removal unit, a higher removal efficiency for the specific impurity can be obtained. For example, impurities such as Pd, Ag, and Au can be removed in both the first impurity removal unit (210) and the second impurity removal unit (220), so that the removal efficiency for specific impurities can be further improved through the continuous treatment device for a vanadium ion-containing electrolyte according to the present invention.

[0062] In addition, different impurities can be removed in the first impurity removal unit (210) and the second impurity removal unit (220). In this case, various types of impurity removal effects can be obtained. For example, in addition to Pd, Ag, and Au, Ni, Cu, etc. can be removed through the first impurity removal unit (210), so that the continuous treatment device for a vanadium ion-containing electrolyte according to the present invention can obtain various impurity removal effects.

[0063]

[0064] Figure 4 schematically illustrates a method for continuously processing a vanadium ion-containing electrolyte according to an embodiment of the present invention.

[0065] Referring to FIG. 4, the illustrated method for continuous treatment of an electrolyte containing vanadium ions includes a vanadium electrolyte supply step (S410), a first treatment step (S420), a second treatment step (S430), and a vanadium electrolyte recovery step (S440).

[0066] First, in the vanadium electrolyte supply step (S410), the vanadium ion-containing electrolyte is separately supplied to the oxidation electrode section and reduction electrode section of the charging cell.

[0067] Next, in the first processing step (S420), an oxidation-reduction reaction is performed on the vanadium ion-containing electrolyte in the charging cell to first electrochemically remove impurities contained in the vanadium ion-containing electrolyte, and then the vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section are mixed.

[0068] Electrochemical removal of impurities in an electrolyte containing vanadium ions utilizes the principle that when the oxidation number of vanadium ions in the electrolyte solution in a charging cell is lower than the precipitation oxidation number of the metal impurity (e.g., 3), the metal impurity is precipitated (adsorbed) from the electrolyte solution to the electrode surface. Based on the standard reduction potential of vanadium, for example, V 3+ / V 2+ If the standard reduction potential of vanadium is -0.25 V, the Mo element, which has a reduction potential of -0.20 V, can be adsorbed on an electrode such as carbon felt during reduction in the reduction electrode section. That is, when an electrolyte containing vanadium and metal impurities undergoes a reduction reaction in a charging cell, the oxidation number of the vanadium ion decreases from, for example, 3.5 to 2, and the metal impurity with a relatively low reduction potential is precipitated, i.e., adsorbed, on the electrode. By this principle, metal impurities can be removed from the vanadium-containing electrolyte, and the concentration of metal impurities in the vanadium-containing electrolyte can be lowered.

[0069] As shown in the example in Fig. 3, the vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.5, the vanadium ion-containing electrolyte passing through the reduction electrode section has a vanadium ion oxidation number of 2 to 3, the vanadium ion-containing electrolyte passing through the oxidation electrode section has a vanadium ion oxidation number of 4 to 5, and the mixed / merged vanadium ion-containing electrolyte may have a vanadium ion oxidation number of +3.5.

[0070] By mixing the vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section, the temperature of the mixed vanadium ion-containing electrolyte can rise to 30 to 60°C.

[0071] Next, in the second processing step (S430), the mixed vanadium ion-containing electrolyte is reacted with an extractant to extract and remove impurities contained in the vanadium ion-containing electrolyte.

[0072] The second impurity removal unit includes an organic layer containing kerosene and an extractant, and as the vanadium ion-containing electrolyte passes through the organic layer, impurities contained in the vanadium ion-containing electrolyte can move to the organic layer.

[0073] In the second processing step (S430), stirring may be performed for 2 to 14 hours so that the electrolyte and organic layer can be sufficiently mixed.

[0074] The extractant may be selected from at least one phosphoric acid extractant such as PC88A (2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester), TOPO (trioctylphosphine oxide), TBP (tributyl phosphate), DBP (dibutyl phosphate), HDEHP (Bis(2-ethylhexyl) hydrogen phosphate) and an amine extractant such as Alamine336.

[0075] In the secondary impurity removal step, the reaction between the extractant and the impurities requires a temperature of 30°C or higher, more preferably 40°C or higher. In the present invention, the temperature of the vanadium ion-containing electrolyte of 30 to 60°C secured in the previous first treatment step (S420) can be used as the reaction temperature.

[0076] Next, in the vanadium electrolyte recovery step (S440), the vanadium ion-containing electrolyte from which impurities have been removed is recovered.

[0077] According to the continuous treatment method of an electrolyte containing vanadium ions according to the present invention, electrochemical impurity removal and impurity removal using an extractant can be performed continuously, and the temperature of the electrolyte obtained in the first treatment step can be utilized as the reaction temperature of the second treatment step, so that a separate heating device can be omitted.

[0078] Example

[0079] Hereinafter, the present invention will be described in more detail by describing experimental examples of the present invention. However, these are only examples of the present invention and the present invention is not limited thereto.

[0080] Using the device shown in Fig. 2, 1 L of a 3.5-valent vanadium ion-containing electrolyte (electrolyte concentration: 1.7 M) was continuously treated. In the treatment of the vanadium ion-containing electrolyte, as shown in Table 1, in Comparative Examples 1 and 2, only the temperature of kerosene was controlled by a heating device without arranging a charging cell for the first impurity removal. In addition, in Comparative Example 3, only a charging cell was arranged and impurity removal using an extractant was not performed. In Comparative Examples 1-2 and Example 1-2, TBP was used as the extractant.

[0081] After treating the electrolyte containing 3.5 vanadium ions under the conditions of Examples 1 to 2 and Comparative Examples 1 to 3, the occurrence of pressure and the degree of pressure increase were evaluated.

[0082] Whether pressure was generated and the degree of pressure increase was measured using the pressure measurement cell shown in Fig. 5.

[0083] The structure of the pressure measurement cell used in the experiment is shown in Fig. 5.

[0084] A reduction electrode part (reduction electrode and electrolyte) (510a) was placed on the upper part of the separator (520), and an oxidation electrode part (oxidation electrode and electrolyte) (510b) was placed on the lower part of the separator. A cell (501) including a carbon collector (530a, 530b) and a metal collector (540a, 540b) was formed on the surface of the reduction electrode part and the oxidation electrode part, and the pressure of the cell was measured through a pressure gauge (550). Carbon felt, size 99*99 mm, was used as the reduction electrode and the oxidation electrode. A 1.7 M vanadium electrolyte was used as the vanadium electrolyte, and the injection amount was 138 g. An ion-selective separator was used as the separator. An aluminum collector was used as the metal collector. A carbon separator was used as the carbon collector. A pressure gauge (550) manufactured by Sensys was used.

[0085] Pressure measurements were performed to determine whether pressure occurred during discharge during the charge / discharge cycle of the pressure measurement cell. Measurements began after 10 cycles to ensure cell stabilization. A total of 100 cycles were performed, and the pressure increase was determined based on the pressure value at cycle 11.

[0086] [Table 1]

[0087]

[0088] Figure 6 shows the pressure measurement results of the examples and comparative examples.

[0089] Referring to Table 1 and Fig. 6, when comparing Comparative Example 1 and Comparative Example 2 (Concept 1), in which only the second impurity removal process was performed without performing the first impurity removal process, no pressure was generated only in Comparative Example 2, in which the kerosene temperature was 40°C, whereas pressure was generated in Comparative Example 1, in which the kerosene temperature was 30°C. In addition, pressure was generated in Comparative Example 3 (Concept 2), in which only the first impurity removal process was performed without the second impurity removal process.

[0090] In both Examples 1 and 2 (Concept 3), which included both the first impurity removal process and the second impurity removal process and increased the temperature of the kerosene in the second impurity removal process using the temperature generated in the first impurity removal process, no pressure was generated. In particular, in the case of Example 1, no pressure was generated even though the kerosene temperature was only 30°C, which means that both the first impurity removal process and the second impurity removal process proceeded smoothly.

[0091] The charging cell of Example 1 was operated at a power of 27 W, and the heating device of Comparative Example 2 was operated at a power of 380 W. Since Example 1 consumes much less power than Comparative Example 2, it can be considered more effective.

[0092] Although the embodiments of the present specification have been described in more detail with reference to the attached drawings, the present specification is not necessarily limited to these embodiments, and various modifications may be implemented without departing from the technical spirit of the present specification. Therefore, the embodiments disclosed in this specification are not intended to limit the technical spirit of the present specification, but to explain, and the scope of the technical spirit of the present specification is not limited by these embodiments. Therefore, it should be understood that the embodiments described above are illustrative in all respects and not restrictive. The scope of protection of this specification should be interpreted by the claims, and all technical ideas within a scope equivalent thereto should be interpreted as being included in the scope of rights of this specification.

Claims

1. A first electrolyte storage unit storing an electrolyte containing vanadium ions; A first impurity removal unit connected to the electrolyte storage unit and performing a charging reaction of an electrolyte containing vanadium ions to primarily remove impurities; A second impurity removal unit for removing impurities for the second time by reacting the vanadium ion-containing electrolyte that has passed through the first impurity removal unit with an extractant; and A device for continuously processing a vanadium ion-containing electrolyte, comprising a second electrolyte storage unit for recovering and storing a vanadium ion-containing electrolyte that has passed through the second impurity removal unit.

2. In paragraph 1, A device for continuously processing a vanadium ion-containing electrolyte, wherein the temperature required for the second impurity removal unit is provided from the first impurity removal unit.

3. In paragraph 1, The above first impurity removal unit includes an oxidation electrode unit and a reduction electrode unit, The above vanadium ion-containing electrolyte is separately supplied to the oxidation electrode part and the reduction electrode part, A device for continuously processing a vanadium ion-containing electrolyte, in which a vanadium ion-containing electrolyte that has passed through the oxidation electrode section and a vanadium ion-containing electrolyte that has passed through the reduction electrode section are combined.

4. In paragraph 3, The above vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.

5. The electrolyte containing vanadium ions passing through the above reduction electrode section has a vanadium ion oxidation number of divalent to trivalent, and the electrolyte containing vanadium ions passing through the above oxidation electrode section has a vanadium ion oxidation number of tetravalent to pentavalent. A device for continuously processing a vanadium ion-containing electrolyte, wherein the combined vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.

5.

5. In paragraph 4, A device for continuously processing a vanadium ion-containing electrolyte, wherein the temperature of the above-mentioned combined vanadium ion-containing electrolyte is 30 to 60°C.

6. In paragraph 1, The second impurity removal unit is a continuous treatment device for a vanadium ion-containing electrolyte, comprising an organic layer containing kerosene and an extractant.

7. A step of separately supplying a vanadium ion-containing electrolyte to the oxidation electrode section and reduction electrode section of the charging cell; A step of first removing impurities contained in the vanadium ion-containing electrolyte by performing an oxidation-reduction reaction on the vanadium ion-containing electrolyte in the above charging cell, and then mixing the vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section; A step of secondary removing impurities contained in the vanadium ion-containing electrolyte by reacting the mixed vanadium ion-containing electrolyte with an extractant; and A method for continuously processing a vanadium ion-containing electrolyte, comprising a step of recovering a vanadium ion-containing electrolyte from which impurities have been removed.

8. In paragraph 7, A method for continuously processing a vanadium ion-containing electrolyte, wherein the temperature of the mixed vanadium ion-containing electrolyte of the oxidation electrode section and the vanadium ion-containing electrolyte of the reduction electrode section is increased to 30 to 60°C.

9. In paragraph 8, A method for continuously processing a vanadium ion-containing electrolyte, wherein a temperature of the vanadium ion-containing electrolyte of 30 to 60°C is used as a reaction temperature in the step of secondary removal of the above impurities.

10. In paragraph 7, The above vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.

5. The electrolyte containing vanadium ions passing through the above reduction electrode section has a vanadium ion oxidation number of divalent to trivalent, and the electrolyte containing vanadium ions passing through the above oxidation electrode section has a vanadium ion oxidation number of tetravalent to pentavalent. A method for continuously processing a vanadium ion-containing electrolyte, wherein the combined vanadium ion-containing electrolyte has a vanadium ion oxidation number of +3.

5.

11. In paragraph 7, A method for continuously treating a vanadium ion-containing electrolyte, wherein the second impurity removing unit includes an organic layer containing kerosene and an extractant, and impurities contained in the vanadium ion-containing electrolyte move to the organic layer as the vanadium ion-containing electrolyte passes through the organic layer.

12. In paragraph 7, A method for continuous treatment of an electrolyte solution containing vanadium ions, wherein the extractant is at least one selected from PC88A (2-Ethylhexyl phosphonic acid mono-2-ethylhexyl ester), TOPO (trioctylphosphine oxide), a phosphoric acid extractant, and an amine extractant.

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