KR20200053814A - Method for recovering lithium element from waste electrode - Google Patents

Abstract

The present invention relates to a method for recovering a lithium element from a waste electrode, the method comprising the steps of: separating an electrode active material layer from a waste electrode collector to obtain an electrode active material powder; heat-treating the electrode active material powder; and immersing the electrode active material powder in distilled water and leaching lithium ions.

Description

METHOD FOR RECOVERING LITHIUM ELEMENT FROM WASTE ELECTRODE

The present invention relates to a method for recovering a lithium component from a waste electrode, and more particularly, to a method for recovering a lithium component from the waste anode of a lithium secondary battery.

A lithium secondary battery is a secondary battery composed of a positive electrode containing a positive electrode active material, a negative electrode containing a negative electrode active material, a separator, and an electrolyte, and charging and discharging by intercalation-decalation of lithium ions. Lithium secondary batteries have a high energy density, a large electromotive force, and have the advantage of exerting a high capacity, and thus have been applied to various fields.

The positive electrode active material of a lithium secondary battery includes, along with lithium, transition metals such as nickel, cobalt, and manganese. The nickel and cobalt are relatively expensive metals. In particular, cobalt has a limited number of producers, and its supply and demand worldwide. It is known as this unstable metal. Therefore, when the transition metal including lithium and cobalt is recovered from the discarded electrode, particularly the anode, and recycled as a raw material, it is possible not only to secure price competitiveness but also to generate additional revenue. Therefore, studies on a method of recovering and recycling metal components from a closed electrode have been attempted.

Conventionally, in order to recover the metal component from the closed electrode, a method of extracting transition metals with an organic extractant after immersing the electrode active material obtained from the closed electrode in a strong acid aqueous solution was used. However, after the electrode active material is leached into the strong acid aqueous solution as described above, when extracting transition metals using an organic extractant, since transition metals such as Mn, Co, and Ni are first extracted, and finally Li is recovered. There is a problem that the recovery rate of Li is low.

In addition, when recovering Li at the end of the recovery process, a large amount of Na introduced in the solvent extraction process of a transition metal such as Co, Ni or a pH adjustment step of the leach solution is present in the leach solution, so that the Na ions are Na ₂ SO ₄ The process of removing in the form of 10H ₂ O must be performed.

Therefore, the recovery rate of Li is improved, and an advantageous recovery method is required in terms of removing impurities.

Republic of Korea Registered Patent No. 1662217

The present invention is to solve the above problems, and to provide a method for recovering lithium components from a closed electrode having a high leaching efficiency of lithium components.

The present invention comprises the steps of separating the electrode active material layer from the current collector of the closed electrode to obtain an electrode active material powder; Heat-treating the electrode active material powder; And immersing the electrode active material powder in distilled water, followed by leaching lithium ions.

According to the present invention, only the lithium component can be selectively recovered by immersing the electrode active material powder in which partial reduction occurs by dipping the electrode active material powder obtained from the closed electrode by heat treatment at a high temperature.

1 is a view showing the XRD pattern of the lithium component recovered in the present invention.

Hereinafter, the present invention will be described in more detail.

The terms or words used in the specification and claims should not be interpreted as being limited to ordinary or lexical meanings, and the inventor can appropriately define the concept of terms in order to explain his or her invention in the best way. Based on the principle that it should be interpreted as meanings and concepts consistent with the technical spirit of the present invention.

The terminology used herein is only used to describe exemplary embodiments, and is not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

In this specification, terms such as “include”, “have” or “have” are intended to indicate that an implemented feature, number, step, component, or combination thereof exists, and that one or more other features or It does not exclude the possibility or presence of numbers, steps, elements, or combinations thereof.

Hereinafter, the present invention will be described in detail.

The method for recovering the lithium component from the waste electrode according to the present invention comprises: separating the electrode active material layer from the current collector of the waste electrode to obtain an electrode active material powder by separating the electrode active material layer, and heat-treating the electrode active material powder, And immersing the electrode active material powder in distilled water, followed by leaching lithium ions.

In addition, the method according to the present invention, if necessary, may further include the step of adding hydrazine after the step of heat-treating the electrode active material powder.

In addition, the method according to the present invention, if necessary, may further include a filtration and drying step after the step of leaching lithium ions.

Hereinafter, each step of the present invention will be described in more detail.

First, a closed electrode is prepared.

In the present invention, the waste electrode includes an electrode having a defect in a secondary battery manufacturing process or an electrode separated from the secondary battery that has been discarded after being used. Specifically, the closed electrode may be, for example, a coating failure occurring when the electrode active material slurry is coated, a material that is out of specifications, or an electrode that has exceeded an effective period set during storage among the completed electrodes.

The closed electrode may be a positive electrode or a negative electrode, but considering economics, etc., the closed electrode may be a positive electrode having a large benefit from recycling of the active material.

Specifically, the closed electrode may include a current collector and an electrode active material layer formed on the current collector. The current collector may be a commonly used metal thin film used as an electrode current collector in the art, for example, an aluminum thin film when the closed electrode is an anode, or a copper thin film when the closed electrode is a cathode. Can be

Meanwhile, the electrode active material layer may include an electrode active material, a binder, and / or a conductive material.

The electrode active material is preferably a positive electrode active material including at least one transition metal of lithium, nickel, cobalt, and manganese. As a specific example, the positive electrode active material, lithium cobalt oxide (LiCoO ₂ ); Lithium nickel oxide (LiNiO ₂ ); Li [Ni _a Co _b Mn _c M ¹ _d ] O ₂ (In the above formula, M ¹ is any one selected from the group consisting of Al, Ga and In, or two or more of them, 0.3≤a <1.0, 0 ≤b≤0.5, 0≤c≤0.5, 0≤d≤0.1, a + b + c + d = 1); Li (Li _e M ² _{fe-f '} M ³ _f' ) O _{2 - g} A _g (where 0≤e≤0.2, 0.6≤f≤1, 0≤f'≤0.2, 0≤g≤0.2 , M ² includes one or more selected from the group consisting of Mn, Ni, Co, Fe, Cr, V, Cu, Zn, and Ti, and M ³ is 1 selected from the group consisting of Al, Mg, and B Or more, and A is one or more selected from the group consisting of P, F, S, and N) or a compound substituted with one or more transition metals; Lithium manganese oxides such as Li _{1 + h} Mn _2-h O ₄ (0 ≦ _h ≦ 0.33 in the above formula), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ ; Ni-site type lithium nickel oxide represented by the formula LiNi _{1 - i} M ⁴ _i O ₂ (wherein M ⁴ = Co, Mn, Al, Cu, Fe, Mg, B or Ga, and 0.01≤i≤0.3); Formula LiMn _{2 - j} M ⁵ _j O ₂ (In the above formula, M ⁵ = Co, Ni, Fe, Cr, Zn or Ta, 0.01≤j≤0.1) or Li ₂ Mn ₃ M ⁶ O ₈ (In the above formula, M ⁶ = lithium manganese complex oxide represented by Fe, Co, Ni, Cu or Zn); LiMn ₂ O _{4 in} which part of Li in the formula is substituted with alkaline earth metal ions Etc. Preferably, the positive electrode active material may be a lithium nickel cobalt manganese oxide including nickel, cobalt, and manganese as a transition metal.

The binder serves to improve adhesion between the electrode active material particles and the adhesion between the electrode active material and the current collector, and general electrode binders used in the art may be used. Specific examples of the binder include polyvinylidene fluoride (PVDF), vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinyl alcohol, polyacrylonitrile, carboxymethyl cellulose Woods (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene polymer (EPDM), sulfonated-EPDM, Styrene butadiene rubber (SBR), fluorine rubber, or various copolymers thereof, and one or a mixture of two or more of them may be used.

The conductive material is used to impart conductivity to the electrode, and in the battery to be constructed, it can be used without particular limitation as long as it has electronic conductivity without causing chemical change. Specific examples include graphite such as natural graphite and artificial graphite; Carbon-based materials such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, thermal black, and carbon fiber; Metal powders or metal fibers such as copper, nickel, aluminum, and silver; Conductive whiskers such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Or a conductive polymer, such as a polyphenylene derivative, and the like, or a mixture of two or more of them may be used.

When the closed electrode is prepared, the electrode active material layer is separated from the current collector of the closed electrode to obtain an electrode active material powder.

The separation may be performed through methods known in the art, and the method is not particularly limited. For example, the separation may be performed using a physical method of scraping or crushing the electrode active material layer on the current collector, or a chemical method of dissolving and dissolving the binder component by immersing the waste electrode in an organic solvent. have.

 Next, the obtained electrode active material powder is heat treated.

In the present invention, by heat-treating the electrode active material powder separated from the current collector, carbonization of a binder and a conductive material component that may remain in the electrode active material powder separated from the closed electrode prevents the electrode active material powder from remaining in the electrode at the same time Partially reducing the active material powder may increase the leaching efficiency of the Li component in the leaching process described below, and minimize loss of lithium.

Conventionally, in order to facilitate separation of the current collector and the electrode active material layer from the closed electrode, a technique of carbonizing a binder or the like by performing heat treatment was used, but in this case, the heat treatment is performed with the electrode active material layer attached to the current collector. , When heat treatment was performed at a temperature exceeding 500 ° C., there was a problem in that aluminum was mixed into the electrode active material powder obtained from the closed electrode by breaking the current collector even in a light physical impact. As described above, when the electrode active material powder contains aluminum, a process of precipitating and removing the aluminum using a hydroxide salt should be added, and thus the yield of the electrode active material powder finally obtained may be lowered.

In addition, when heat treatment is performed on the waste electrode at a temperature of 500 ° C. or less, complete oxidation of the conductive material and the binder is impossible in the temperature range, so that the binder may remain in the electrode active material powder finally obtained, thereby improving the leaching rate of Li. It can decrease.

On the other hand, the heat treatment of the electrode active material powder is from 400 ° C to 700 ° C for 1 hour to 10 hours, preferably from 500 ° C to 600 ° C, more preferably from 530 ° C to 600 ° C, most preferably from 550 ° C to 600 ° C It may be performed for 1 hour to 5 hours. When heat treatment of the electrode active material powder is performed in the above range, the conductive material and organic binder remaining in the electrode active material powder are oxidized and removed through the heat treatment, and at this time, partial reduction of the electrode active material occurs by consuming lattice oxygen of the electrode active material. Thus, the leaching efficiency of Li may be increased in the leaching process described below.

For example, when the heat treatment temperature is less than 400 ° C., the binder is not completely oxidized and may remain in the electrode active material powder, thereby reducing the leaching rate of Li, and when it exceeds 700 ° C., aggregation of the electrode active material powder Due to the phenomenon, there may be a problem that a physical grinding step must be added during the leaching process.

In addition, when the heat treatment time is less than 1 hour, the effect of improving the leaching rate due to partial reduction of the electrode active material is negligible. When the heat treatment time exceeds 10 hours, there is no additional effect of improving the leaching rate, resulting in poor economic efficiency.

In addition, if necessary, hydrazine may be added to the heat-treated positive electrode active material powder and then mixed. When hydrazine is further added to the positive electrode active material powder, the hydrazine may further reduce the electrode active material to improve the leaching rate and leaching efficiency.

The hydrazine may be in the form of I hydrate. Particularly, hydrazine I hydrate having a purity of 80% may be used, and the hydrazine is 10 to 100 parts by weight, preferably 20 to 100 parts by weight, and more preferably 20 to 90 parts by weight based on 100 parts by weight of the positive electrode active material powder. , Most preferably 40 to 90 may be added. When hydrazine is included in the above range, the leaching rate and leaching efficiency may be most improved. For example, when the hydrazine is added in excess of the above range, securing of economic efficiency due to excessive input of raw materials may be deteriorated. On the other hand, when the hydrazine is added below the above range, the effect of improving the leaching rate of the lithium component due to the addition of the hydrazine cannot be achieved.

Next, after dipping the electrode active material powder in distilled water, lithium ions are leached.

Conventionally, it has been common to leach metal ions containing lithium using a strong acid aqueous solution in order to leach metal components containing lithium from the waste anode. However, since the process of extracting / separating each metal component in the leach solution generally proceeds in the order of Mn, Co, Ni, there was a problem that excess Li is lost in this process, and finally the remaining leach solution is a metal to be recovered Among them, only Li is present, and since the large amount of Na introduced during the leaching process also remains in the leachate, a process of removing Na must be added.

However, as in the present invention, when using distilled water, metal components such as Ni, Co, and Mn are hardly leached in distilled water, and only thermally decomposed Li can be leached. This is because the lattice oxygen of the active material is partially used when thermally decomposing or oxidizing the conductive material and the binder during heat treatment, whereby the electrode active material is partially reduced, and the amount of lithium component leaching from the electrode active material powder can be further increased.

The step of leaching the lithium ions may be performed for 10 minutes to 300 minutes, preferably 30 minutes to 120 minutes. If the leaching time is too short below the above range, the metal component is not sufficiently leached, and if the leaching time is too long beyond the above range, the leaching amount is improved, but economic efficiency is poor.

Meanwhile, in order to improve the leaching efficiency of the metal component, the leaching may be performed at a temperature of 10 ° C to 100 ° C, preferably 30 ° C to 80 ° C.

Through the above-described process, a leachate containing a salt of the lithium component contained in the electrode active material can be obtained.

After obtaining the leach solution containing the lithium component as described above, lithium may be recovered in the form of a lithium salt by using the leach solution containing the lithium component. For example, the leach solution containing the lithium component may be dried to recover lithium salt form (for example, Li ₂ CO ₃ ) lithium. At this time, in order to increase the purity of the lithium salt, a sodium-containing compound such as Na ₂ CO ₃ may be introduced into the leach solution to crystallize into Li ₂ CO ₃ .

Specifically, in order to recover lithium in the form of a lithium salt, first, the leach solution is filtered. The filtration may be performed by filtering the suspended solids and impurities in the leachate by passing the leachate through a filter containing fine pores. Preferably, the leachate is filtered under reduced pressure by using a filter connected to a vacuum pump or the like. Can be performed.

Then, the filtrate obtained through the filtration process is concentrated by a method such as drying under reduced pressure, and Na ₂ CO ₃ or NaOH is added to separate Li ions into a lithium salt.

For example, the concentration is preferably carried out at the temperature and pressure immediately before the filtrate is boiled, for example, it may be carried out at a pressure of 60 ~ 80 ℃, 100 ~ 500mbar, but is not limited thereto.

For example, by adding Na ₂ CO ₃ to the filtrate, the Li component is precipitated in Li ₂ CO ₃ form and crystallized, and then filtered to obtain a Li ₂ CO ₃ form lithium salt.

When the above process is performed, lithium salt can be selectively obtained from the electrode active material obtained from the closed electrode, and the obtained product can be recycled as a raw material for the electrode active material.

On the other hand, in the case of the electrode active material, which heat-treated the electrode active material as in the present invention, and immersed in distilled water and selectively leached only Li ions, if necessary, recover the electrode active material that leached the Li component and use a strong acid aqueous solution as in the prior art By additionally performing the leaching process, not only the unleached lithium component but also the transition metal component included in the electrode active material is additionally leached to increase the recovery rate of the transition metal, but is not limited thereto.

Hereinafter, examples will be described in detail to specifically describe the present invention. However, the embodiments according to the present invention may be modified in various other forms, and the scope of the present invention should not be construed as being limited to the embodiments described below. The embodiments of the present invention are provided to more fully describe the present invention to those skilled in the art.

Example

Example  One

A waste anode comprising Li [Ni _0.6 Co _0.2 Mn _0.2 ] O ₂ as a positive electrode active material was prepared. Subsequently, the positive electrode active material layer was scraped from the current collector of the waste positive electrode to obtain a positive electrode active material powder. 5 g of the positive electrode active material powder obtained as described above was heat treated at 550 ° C. for 3 hours, then mixed with 100 g of distilled water and stirred at room temperature (30 ° C.) for 65 hours to obtain a leachate in which lithium ions were leached.

Example  2 ~ Example  16

The positive electrode active material powder content, distilled water content, agitation temperature, agitation time, and hydrazine content were carried out in the same manner as in Example 1, except for controlling as shown in Table 1 below.

Powder content (g) Distilled water content (g) Stirring temperature (℃) Stirring time (hr) 80% purity hydrazine content (g) Example 1 5 100 30 65 0 Example 2 5 100 30 100 0 Example 3 15 300 30 0.5 0 Example 4 15 300 50 0.5 0 Example 5 15 300 80 0.5 0 Example 6 15 300 30 2 0 Example 7 15 300 50 2 0 Example 8 15 300 80 2 0 Example 9 15 200 30 2 0 Example 10 15 100 30 2 0 Example 11 10 50 30 2 0 Example 12 10 50 30 2 2.25 Example 13 10 50 30 2 4.5 Example 14 10 50 30 2 6.75 Example 15 10 50 30 2 9 Example 16 10 59 30 2 0

Comparative example  1 ~ 14

The positive electrode active material powder obtained from the waste anode was not heat-treated, and was carried out in the same manner as in Example 1, except that the positive electrode active material powder content, distilled water content, stirring temperature, stirring time, and hydrazine content were controlled as shown in Table 2 below. Did.

Powder content (g) Distilled water content (g) Stirring temperature (℃) Stirring time (hr) 80% purity hydrazine content (g) Comparative Example 1 5 100 30 65 0 Comparative Example 2 5 100 30 100 0 Comparative Example 3 15 300 30 0.5 0 Comparative Example 4 15 300 50 0.5 0 Comparative Example 5 15 300 80 0.5 0 Comparative Example 6 15 300 30 2 0 Comparative Example 7 15 300 50 2 0 Comparative Example 8 15 300 80 2 0 Comparative Example 9 10 50 30 2 0 Comparative Example 10 10 50 30 2 2.25 Comparative Example 11 10 50 30 2 4.5 Comparative Example 12 10 50 30 2 6.75 Comparative Example 13 10 50 30 2 9 Comparative Example 14 10 59 30 2 0

Comparative example  15

The waste anode was heat-treated at 500 ° C. for 1 hour to separate the positive electrode active material from the waste anode, and 15 g of the positive electrode active material powder separated above was mixed with 300 g of distilled water and stirred at room temperature for 0.5 hour to obtain a leaching solution from which lithium ions leached.

Experimental Example  One

The leaching amount of lithium, nickel, manganese and cobalt in the leachate obtained by Examples 1 to 16 and Comparative Examples 1 to 15 was measured using an inductively coupled plasma spectrometer (ICP-OES). In addition, the amount of leaching measured by the above method was multiplied by the total weight of the filtrate, and then divided by the content of metal in the raw material to measure the leaching rate of each metal component, and the results are shown in Table 3 below.

Metal leaching amount (ppm) Leaching rate (%) Li Ni Co Mn Example 1 845 <1 <1 <1 24.9 Example 2 850 <1 <1 <1 25.0 Example 3 800 <1 <1 <1 21.9 Example 4 815 <1 <1 <1 22.3 Example 5 860 <1 <1 <1 23.6 Example 6 830 <1 <1 <1 22.7 Example 7 840 <1 <1 <1 23.0 Example 8 880 <1 <1 <1 24.1 Example 9 1170 <1 <1 <1 21.4 Example 10 1850 <1 <1 <1 16.9 Example 11 2080 <10 <10 <10 11.6 Example 12 2595 <10 <10 <10 16.2 Example 13 2665 <10 <10 <10 17.2 Example 14 2400 <10 <10 <10 17.8 Example 15 2795 <10 <10 <10 21.0 Example 16 1720 <10 <10 <10 13.1 Comparative Example 1 152 <1 <1 <1 4.5 Comparative Example 2 168 <1 <1 <1 4.9 Comparative Example 3 115 <1 <1 <1 3.4 Comparative Example 4 125 <1 <1 <1 3.7 Comparative Example 5 220 <1 <1 <1 6.5 Comparative Example 6 115 <1 <1 <1 3.4 Comparative Example 7 140 <1 <1 <1 4.1 Comparative Example 8 255 <1 <1 <1 7.5 Comparative Example 9 425 <10 <10 <10 2.9 Comparative Example 10 425 <10 <10 <10 3.0 Comparative Example 11 400 <10 <10 <10 2.9 Comparative Example 12 405 <10 <10 <10 3.1 Comparative Example 13 420 <10 <10 <10 3.4 Comparative Example 14 360 <10 <10 <10 3.0 Comparative Example 15 660 <1 <1 <1 18.1

As shown in Table 3, in the case of Examples 1 to 16 in which the positive electrode active material powder was obtained and heat-treated, it was confirmed that the leaching amount of Li was greater than Comparative Examples 1 to 15 in which the heat treatment process was not performed. Further, referring to Examples 1 to 8 and Comparative Examples 1 to 8, it was confirmed that the leaching rate increased as the stirring temperature and the stirring time increased. However, when the stirring time is longer than a certain time, since the leaching rate improvement was not remarkable compared to the stirring time, it was confirmed that it is economical to improve the leaching amount by simultaneously controlling the stirring temperature and the stirring time.

In addition, when Examples 3 to 5, Comparative Examples 3 to 5, and Comparative Example 15 were confirmed, when the positive electrode active material powder content, distilled water content, and stirring time were the same, the positive electrode active material powder was obtained and heat treated in Examples 3 to 5 In the case, it was confirmed that the leaching amount of Li was significantly higher than Comparative Examples 3 to 5 in which the heat treatment process was not performed. In addition, in the case of Comparative Example 15 in which the anode was heat-treated and the cathode active material powder was obtained therefrom, the leaching rate due to the partial reduction of the cathode active material was higher than in Comparative Examples 3 to 5 without performing the heat treatment process. It was confirmed that the leaching amount of Li was lower than those of Examples 3 to 5 in which the obtained positive electrode active material powder was heat-treated.

Further, when Examples 6, 9 and 10 were confirmed, it was confirmed that when the stirring temperature and the stirring time were the same, the leaching rate of Li also improved as the amount of distilled water increased.

Further, referring to Examples 11 to 16 and Comparative Examples 9 to 14, after obtaining and heat-treating the positive electrode active material powder, when adding an inorganic reducing agent, the higher the content of the inorganic reducing agent, the higher the leaching rate of Li is significantly improved. I could confirm. However, when the positive electrode active material powder was not heat treated, it was confirmed that even if an inorganic reducing agent was added, the effect of improving the Li leaching rate was negligible.

Experimental Example  2

3 cc of the supernatant of the leach solution of Example 10 was taken and filtered through a syringe filter having a pore size of 0.45 μm. Subsequently, 90.7 g of the filtrate was dried under reduced pressure at 68 ° C. under 300 mbar. When the filtrate reached 50 g, drying under reduced pressure was ended. 1.79 g of Na ₂ CO ₃ was dissolved in 8.21 g of distilled water, and then slowly added to the filtrate. Subsequently, drying under reduced pressure was performed again under a condition of 300 mbar at 68 ° C, and drying under reduced pressure was terminated at the time when the precipitate was formed, and then filtration under reduced pressure was performed using a filter paper having a pore size of 2.5 μm.

At this time, in order to remove impurities remaining in the filtrate after the filtration under reduced pressure, the filtrate was washed with 30 mL of distilled water, and then the filtrate was vacuum dried at 60 ° C., whereby the crystal structure of the recovered powder was analyzed. Did. Crystal analysis of the powder was performed through XRD, and the results are shown in FIG. 1.

1, it was confirmed that the recovered powder exhibited a Li ₂ CO ₃ phase.

Claims (7)

Separating the electrode active material layer from the current collector of the closed electrode to obtain an electrode active material powder;
Heat-treating the electrode active material powder; And,
After immersing the electrode active material powder in distilled water, the step of leaching lithium ions; Method for recovering the lithium component from the waste electrode comprising a.
According to claim 1,
The electrode active material powder, lithium, nickel, cobalt and a method for recovering a lithium component from a closed electrode, which comprises a positive electrode active material comprising at least one transition metal of manganese.
According to claim 1,
The heat treatment is performed by maintaining for 1 hour to 10 hours at 400 ℃ to 700 ℃, a method for recovering the lithium component from the closed electrode.
According to claim 1,
After the heat treatment of the electrode active material powder, the method further comprising the step of adding hydrazine prior to immersion in distilled water, the method for recovering the lithium component from the closed electrode.
The method of claim 4,
The hydrazine is added to 1 to 15 parts by weight based on 100 parts by weight of the electrode active material powder, a method for recovering the lithium component from the closed electrode.
According to claim 1,
The step of leaching the lithium ions is performed for 10 minutes to 300 minutes, the method of recovering the lithium component from the closed electrode.
According to claim 1,
After the step of leaching the lithium ions, the lithium component is extracted from the leachate from which the lithium component is leached, filtered, and the filtrate containing the lithium component is purified to crystallize in the form of lithium salt. How to recover the ingredients.

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