Method for separating lithium precursor and system for separating lithium precursor

Abstract

The method for isolating a lithium precursor according to the embodiment of the present application includes the steps of preparing a primary precursor mixture including a primary lithium precursor and a primary transition metal precursor, mixing the primary precursor mixture with a precipitation solution in a reactor to form a precursor mixture, and injecting a non-reactive gas into the precursor mixture. Accordingly, the lithium precursor can be isolated with high purity and high efficiency.

Description

Methods and systems for separating lithium precursors

[0001] This application is a divisional application of Chinese Patent Application No. 202080037222.4, filed on March 30, 2020, entitled "Method and System for Separating Lithium Precursors", and claims priority to Chinese Patent Application No. 10-2019-0058661, filed with the Korean Intellectual Property Office (KIPO) on May 20, 2019, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to a method and a system for separating lithium precursors. More specifically, this invention relates to a method and a system for separating lithium precursors from a primary precursor mixture. Background Technology

[0003] With the development of information and display technologies, rechargeable and dischargeable secondary batteries have been widely used as power sources for mobile electronic devices such as portable cameras, mobile phones, and laptops. Secondary batteries include, for example, lithium-ion batteries, nickel-cadmium batteries, and nickel-metal hydride batteries. Lithium-ion batteries are being actively developed and applied due to their high operating voltage and energy density per unit weight, high charge rate, and compact size.

[0004] A lithium secondary battery may include an electrode assembly comprising a positive electrode, a negative electrode, and a separator layer (separator), as well as an electrolyte immersing the electrode assembly. The lithium secondary battery may further include a housing having, for example, a pouch shape for containing the electrode assembly and the electrolyte.

[0005] Lithium metal oxides can be used as positive electrode active materials in lithium secondary batteries. Lithium metal oxides may also contain transition metals such as nickel, cobalt, and manganese.

[0006] Lithium metal oxides, which can be used as positive electrode active materials, can be prepared by reacting lithium precursors with nickel-cobalt-manganese (NCM) precursors containing nickel, cobalt, and manganese.

[0007] The use of these expensive precious metals in cathode active materials results in excessively high costs during their manufacture. Furthermore, with the increasing prominence of environmental protection issues, methods for recycling cathode active materials have been researched. For the recycling of cathode active materials, it is necessary to regenerate lithium precursors from used cathodes with high efficiency and high yield.

[0008] For example, Korean Patent Application No. 2015-0002963 discloses a method for recovering lithium using a wet process. However, lithium is recovered from waste liquid remaining after the extraction of cobalt, nickel, etc., through a wet process, so the recovery rate may be excessively reduced, and a large number of impurities may be generated from the waste liquid.

[0009] [Technical Objective]

[0010] According to one aspect of the present invention, a method for separating lithium precursors with high efficiency and high purity is provided.

[0011] According to one aspect of the present invention, a system for separating lithium precursors with high efficiency and high purity is provided.

[0012] [Methods to achieve the goal]

[0013] In a method for separating lithium precursors according to an exemplary embodiment, a primary precursor mixture comprising a primary lithium precursor and a primary transition metal precursor is prepared. This primary precursor mixture is mixed with a precipitate in a reactor to form a precursor mixture. A non-reactive gas is injected into the precursor mixture.

[0014] In some implementations, the reactor may be a fluidized bed reactor.

[0015] In some implementations, the primary precursor mixture can be prepared by reducing the positive electrode active material collected from a lithium secondary battery.

[0016] In some implementations, the reduction reaction can be carried out before the precursor mixture is formed in the reactor.

[0017] In some implementations, the primary lithium precursor may include lithium hydroxide.

[0018] In some implementations, the primary lithium precursor may further comprise lithium oxide or lithium carbonate.

[0019] In some implementations, a precursor mixture can be formed by selectively dissolving lithium hydroxide in a precipitate solution.

[0020] In some implementations, the precipitate may include water.

[0021] In some implementations, the precipitate may further comprise dimethyl carbonate or diethyl carbonate.

[0022] In some implementations, the mass of the precipitate in the precursor mixture can be 2 to 20 times the mass of the primary lithium precursor.

[0023] In some embodiments, the precursor mixture may include a slurry or solution containing a primary precursor mixture.

[0024] In some embodiments, injecting a non-reactive gas into the precursor mixture may include pulse injection of the non-reactive gas.

[0025] In some implementations, the solubility of the non-reactive gas in the precipitate can be below 1.5 g / L.

[0026] In some embodiments, the non-reactive gas may include at least one selected from nitrogen, neon, argon, krypton, and xenon.

[0027] In some implementations, non-reactive gases can be injected into the lower part of the reactor.

[0028] In some implementations, injecting a non-reactive gas may include reducing the linear velocity of the non-reactive gas at the top of the reactor.

[0029] In some implementations, the linear velocity of the non-reactive gas can be reduced to 0.1 cm / s to 3 cm / s.

[0030] In some embodiments, the upper part of the reactor may include an expansion section with an extended diameter or an extended width.

[0031] In some implementations, the formation of the precursor mixture and the injection of the non-reactive gas can be repeated in multiple cycles.

[0032] A system for separating lithium precursors according to an exemplary embodiment includes a reactor body in which the lithium precursor is introduced, a precipitate injection unit for injecting precipitate into the reactor body, a gas injection unit for injecting non-reactive gas into the lower part of the reactor body, and an expansion section extending from the upper part of the reactor body and having an extended diameter or an extended width.

[0033] [Effects of the Invention]

[0034] According to the above exemplary embodiments, a primary precursor mixture including a primary lithium precursor and a primary transition metal precursor can be mixed with a precipitate in a reactor to form a precursor mixture, and a non-reactive gas can be injected into the precursor mixture to separate the lithium precursor with high purity and high efficiency.

[0035] Non-reactive gases can disperse the primary precursor mixture in the precipitate, thereby selectively dissolving the lithium precursor containing lithium hydroxide in the precipitate. Additionally, primary transition metal precursors that are not dissolved in the precipitate may precipitate.

[0036] Therefore, lithium precursors can be selectively separated from the primary precursor mixture. Attached Figure Description

[0037] Figure 1 is a process flow diagram illustrating a method for separating lithium precursors according to an exemplary embodiment.

[0038] Figure 2 is a schematic diagram illustrating a system for separating lithium precursors according to an exemplary embodiment. Detailed Implementation

[0039] According to an exemplary embodiment of the present invention, a method and a system for separating lithium precursors are provided, wherein a primary precursor mixture is mixed with a precipitate in a reactor to form a precursor mixture, and a non-reactive gas is injected into the precursor mixture to separate the lithium precursors with high efficiency and high purity.

[0040] In the following, embodiments of the invention will be described in detail with reference to the accompanying drawings. However, the embodiments are provided as exemplary examples, and the spirit of the invention is not limited to the specific embodiments.

[0041] The term "precursor" in this specification is used in general to refer to a compound containing a specific metal to provide a specific metal contained in an electrode active material.

[0042] Figure 1 is a process flow diagram illustrating a method for separating lithium precursors according to an exemplary embodiment. Figure 2 is a schematic diagram illustrating a system for separating lithium precursors according to an exemplary embodiment.

[0043] The methods and systems for separating lithium precursors are described below with reference to Figures 1 and 2.

[0044] Referring to Figure 1, a primary precursor mixture comprising a primary lithium precursor and a primary transition metal precursor can be prepared (e.g., in step S10).

[0045] In an exemplary embodiment, a primary precursor mixture comprising a primary lithium precursor and a primary transition metal precursor can be obtained from a mixture of positive electrode active materials collected from a lithium secondary battery. For example, a mixture of positive electrode active materials can be obtained from a lithium-containing compound obtained from a lithium secondary battery.

[0046] A lithium secondary battery may include an electrode assembly comprising a positive electrode, a negative electrode, and a separator layer between the positive and negative electrodes. The positive and negative electrodes may include a positive electrode active material layer and a negative electrode active material layer respectively coated on a positive electrode current collector and a negative electrode current collector.

[0047] For example, the positive electrode active material contained in the positive electrode active material layer may include oxides containing lithium and transition metals.

[0048] In some implementations, the positive electrode active material may include a compound represented by the following chemical formula 1.

[0049] [Chemical Formula 1]

[0050] Li x M1 a M2 b M3 c O y

[0051] In Chemical Formula 1, M1, M2, and M3 may each independently be selected from Ni, Co, Mn, Na, Mg, Ca, Ti, V, Cr, Cu, Zn, Ge, Sr, Ag, Ba, Zr, Nb, Mo, Al, Ga, or B. In Chemical Formula 1, 0 < x ≤ 1.1, 2 ≤ y ≤ 2.02, 0 < a < 1, 0 < b < 1, 0 < c < 1, and 0 < a + b + c ≤ 1.

[0052] In some embodiments, the positive electrode active material may be an NCM-based lithium oxide containing nickel, cobalt, and manganese. The NCM-based lithium oxide as the positive electrode active material may be prepared by reacting a lithium precursor and an NCM precursor (e.g., an NCM oxide) with each other through, for example, a coprecipitation reaction.

[0053] However, generally, the embodiments of the present invention can be applied not only to positive electrode materials including NCM-based lithium oxides but also to lithium-containing electrode materials.

[0054] The lithium precursor may include lithium hydroxide (LiOH), lithium oxide (Li2O), or lithium carbonate (Li2CO3). Lithium hydroxide may be advantageous as the lithium precursor in terms of the charge / discharge performance, life performance, high-temperature stability, etc. of the lithium secondary battery. For example, lithium carbonate may cause an immersion reaction on the separator layer, thereby reducing life stability.

[0055] Therefore, according to an embodiment of the present invention, a method for highly selectively separating lithium hydroxide as a lithium precursor can be provided.

[0056] For example, the positive electrode can be separated and recovered from the lithium secondary battery. The positive electrode may include a positive electrode current collector (e.g., aluminum (Al)) and a positive electrode active material layer, and the positive electrode active material layer may include a conductive material, a binder, and the above positive electrode active material.

[0057] The conductive material may include, for example, a carbon-based material such as graphite, carbon black, graphene, carbon nanotubes, etc. The binder may include a resin material such as a vinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride (PVDF), polyacrylonitrile, polymethyl methacrylate, etc.

[0058] A mixture of positive electrode active materials can be prepared from recycled positive electrode material. In some embodiments, the mixture of positive electrode active materials can be prepared in powder form by physical methods such as milling. The mixture of positive electrode active materials may include powders of lithium transition metal oxides, and may include, for example, NCM-based lithium oxide powders (e.g., Li(NCM)O2).

[0059] In some embodiments, the positive electrode active material mixture can be heat-treated prior to the grinding process. In this case, the positive electrode current collector can be more easily separated from the positive electrode before the grinding process, and the binder and conductive material can be removed. For example, the heat treatment temperature can be in the range of about 100°C to about 500°C, preferably in the range of about 350°C to about 450°C.

[0060] In some implementations, a mixture of positive electrode active materials can be obtained after immersing the recovered positive electrode in an organic solvent. For example, the recovered positive electrode can be immersed in an organic solvent to separate and remove the positive electrode current collector, and the positive electrode active material can be selectively extracted by centrifugation.

[0061] The above method can essentially completely separate and remove positive electrode current collector components such as aluminum, and can obtain a mixture of positive electrode active materials from which the content of carbon-based components derived from conductive materials and binders may be removed or reduced.

[0062] In some implementations, a primary precursor mixture can be generated by reducing a mixture of positive electrode active materials (e.g., positive electrode active materials). For example, a primary precursor mixture can be formed by reducing a mixture of positive electrode active materials with hydrogen.

[0063] The hydrogen reduction reaction can be carried out at a temperature of about 350°C to about 700°C, preferably about 400°C to about 550°C.

[0064] The primary precursor mixture may include primary lithium precursors and primary transition metal precursors, which may be products of the hydrogen reduction reaction of lithium-transition metal oxides contained in the positive electrode active material mixture.

[0065] Primary lithium precursors may include lithium hydroxide, lithium oxide, and / or lithium carbonate. In an exemplary embodiment, the primary lithium precursor can be obtained via a hydrogen reduction reaction, thereby reducing the mixed content of lithium carbonate.

[0066] Primary transition metal precursors can include Ni, Co, NiO, CoO, MnO, etc.

[0067] For example, the primary precursor mixture formed by the reduction reaction described above can be transferred to reactor 100 as described below.

[0068] In some embodiments, the reduction reaction can be carried out in reactor 100, and the reaction for forming the primary precursor mixture 50 and the precipitate 80 can be carried out in reactor 100 as described below. In this case, the formation reaction of the precursor mixture can be carried out without transferring the primary precursor mixture. Therefore, the yield reduction caused by transferring the primary precursor mixture can be prevented.

[0069] Referring to Figures 1 and 2, the primary precursor mixture 50 and the precipitate 80 can be mixed in reactor 100 to form a precursor mixture (e.g., in step S20).

[0070] For example, a precursor mixture may refer to a composition comprising a lithium precursor formed by reacting a primary lithium precursor 60 with a precipitate 80 and a primary transition metal precursor 70 precipitated in the precipitate 80.

[0071] In some embodiments, reactor 100 may be a fluidized bed reactor. For example, a fluidized bed reactor may refer to a reactor in which a fluid (gas or liquid) flows through an injected primary precursor mixture 50 to induce fluidization. For example, as will be described below, the fluid may be a non-reactive gas.

[0072] For example, the primary precursor mixture 50 can be fluidized in a fluidized bed reactor, thereby increasing the contact area with the precipitate 80. This further promotes the reaction between the primary lithium precursor 60 and the precipitate 80.

[0073] In addition, the primary transition metal precursor 70 can be formed in a slurry state that is easily transferred to subsequent reactors and precipitated in the precipitate 80.

[0074] Referring to Figure 2, the precipitate 80 can be injected into the reactor 100 through the precipitate injection unit 120. The precipitate 80 can also be injected into the reactor body 110 through the precipitate injection unit 120.

[0075] For example, the precipitate injection unit 120 can be located at the upper part of the reactor body 110. The precipitate injection unit 120 can also be located at the lower or middle part of the reactor body 110.

[0076] In some embodiments, the primary lithium precursor may include lithium hydroxide. In some embodiments, the primary lithium precursor may further include lithium oxide or lithium carbonate.

[0077] In some implementations, a precursor mixture can be formed by dissolving the primary lithium precursor 60 in the precipitate 80.

[0078] For example, lithium hydroxide contained in the primary lithium precursor 60 can be selectively dissolved in the precipitate 80 to form a precursor mixture. For example, lithium oxide can react with the precipitate 80 to form lithium hydroxide, which can then be dissolved in the precipitate 80. For example, lithium carbonate may have low solubility in the precipitate 80. Therefore, lithium carbonate can be precipitated and removed from the primary precursor mixture.

[0079] In some embodiments, the precipitate 80 may include water. For example, the primary lithium precursor 60 may be hydrated with water to form a precursor mixture comprising an aqueous solution of dissolved lithium hydroxide.

[0080] In some exemplary embodiments, the precipitate may further comprise dimethyl carbonate or diethyl carbonate.

[0081] For example, dimethyl carbonate or diethyl carbonate can promote the reaction between primary lithium precursor 60 and water. Therefore, the separation efficiency of the lithium precursor can be improved.

[0082] In some embodiments, the mass of the precipitate 80 in the precursor mixture may be about 2 to 20 times the mass of the primary lithium precursor 60, preferably about 2 to 10 times the mass of the primary lithium precursor 60.

[0083] For example, within the aforementioned range, as described below, the primary lithium precursor 60 and the precipitate 80 can be easily mixed using a non-reactive gas. Therefore, the lithium precursor can be separated with high purity and high efficiency without the use of excessive precipitate.

[0084] In some embodiments, the precursor mixture may include a slurry or solution comprising a primary precursor mixture 50.

[0085] For example, a primary transition metal precursor 70 that may be insoluble in the precipitate 80 can be dispersed in the precipitate 80 to form a slurry. For example, lithium hydroxide contained in the primary lithium precursor 60 can be dissolved in the precipitate 80 to form a solution. Therefore, the primary transition metal precursor 70 and the primary lithium precursor 60 can be separated from each other.

[0086] Referring to Figures 1 and 2, a non-reactive gas can be injected into the precursor mixture (e.g., in step S30). For example, a non-reactive gas can be injected into the precursor mixture located inside the reactor 100 via the gas injection unit 130.

[0087] For example, a non-reactive gas can be injected into the precursor mixture to promote the mixing of the primary precursor mixture 50 with the precipitate 80.

[0088] For example, a non-reactive gas can exert a physical impact on the agglomerated primary precursor mixture 50, so that the primary precursor mixture 50 can be uniformly dispersed in the precipitate 80.

[0089] Therefore, the contact area between the precipitate 80 and the primary precursor mixture 50 can be increased, making it easier to form the precursor mixture.

[0090] In some embodiments, a pulse of nonreactive gas can be injected into the precursor mixture. The pulse of the nonreactive gas can comprise a constant periodic variation of the injection rate or amount of the nonreactive gas. For example, the type of pulse can be appropriately selected based on the capacity and shape of the reactor 100.

[0091] In some exemplary embodiments, the solubility of the non-reactive gas in the precipitate 80 may be below 1.5 g / L. Low solubility of the non-reactive gas in the precipitate may be advantageous, and there is no particular limitation on the lower limit of solubility.

[0092] In some exemplary embodiments, the non-reactive gas may include at least one selected from nitrogen, neon, argon, krypton, and xenon, which have low solubility and reactivity relative to the precipitate.

[0093] In this way, the loss of non-reactive gases, which would otherwise occur when they dissolve in the precipitate, can be prevented. Furthermore, the non-reactive gases do not react with the precursor mixture, thus preventing a decrease in the lithium precursor yield due to side reactions.

[0094] In some implementations, the non-reactive gas may not include carbon dioxide (CO2). Therefore, a decrease in lithium precursor yield due to the reaction between carbon dioxide and lithium hydroxide can be prevented.

[0095] In some embodiments, a non-reactive gas may be injected into the lower part of the reactor 100. For example, a non-reactive gas may be injected into the precursor mixture through a gas injection unit 130 located at the lower part of the reactor 100.

[0096] The non-reactive gas injected into the lower part of reactor 100 can rise to the upper part of reactor 100 to promote the mixing of the primary precursor mixture 50 and the precipitate 80 in the entire reactor body 110.

[0097] In some embodiments, the linear velocity (cm / s) of the non-reactive gas injected into the precursor mixture can be from about 5 cm / s to 30 cm / s.

[0098] Within the aforementioned range, the non-reactive gas can provide sufficient physical impact to the aggregated primary precursor mixture 50, thereby further promoting the mixing of the primary precursor mixture 50 and the precipitate 80.

[0099] In some embodiments, the non-reactive gas at the top of reactor 100 may have a reduced linear velocity (cm / s). For example, linear velocity may refer to the flow rate of gas per unit area.

[0100] For example, the mass of each particle in the primary precursor mixture 50 contained in reactor 100 may be different from that of the others. In this case, particles of the primary precursor mixture 50 with relatively small masses may exit the reactor body 110 via a non-reactive gas flow, or may settle in the upper part of reactor 100.

[0101] Therefore, the linear velocity (cm / s) of the non-reactive gas at the top of the reactor 100 can be reduced, thereby effectively preventing the primary precursor mixture 50 from flowing out of the reactor body 110 or settling at the top of the reactor 100.

[0102] In some embodiments, the linear velocity of the non-reactive gas at the top of reactor 100 can be reduced to about 0.1 cm / s to 3 cm / s. For example, the linear velocity of the non-reactive gas in the expansion section 140 located at the top of reactor body 110 can be reduced to about 0.1 cm / s to 3 cm / s.

[0103] Within the aforementioned range, the primary precursor mixture 50 can be prevented from flowing out of the reactor body 110, while further promoting the mixing of the primary precursor mixture 50 with the precipitate 80.

[0104] For example, reactor 100 may include an expansion section 140 extending from the upper part of reactor body 110 and having a diameter larger than that of reactor body 110.

[0105] For example, the expansion section 140 may have a larger cross-sectional area than the reactor body 110, so that the linear velocity (cm / s) of the non-reactive gas moving from the reactor body 110 to the expansion section 140 can be reduced. In this case, the ratio of the diameter of the expansion section 140 to the diameter of the reactor body 110 can be adjusted, and thus the rate of reduction of the linear velocity (cm / s) can be easily adjusted.

[0106] In some embodiments, the ratio of the diameter of the expansion section 140 to the diameter of the reactor body 110 can be 2 to 10.

[0107] Within the aforementioned diameter ratio range, it is possible to more effectively prevent the primary precursor mixture 50 from flowing out of the reactor body 110.

[0108] In some exemplary embodiments, the formation of the precursor mixture and the injection of the non-reactive gas can be repeated in multiple cycles.

[0109] For example, the separation efficiency and yield of lithium precursors can be improved by repeatedly forming precursor mixtures and injecting non-reactive gases.

[0110] For example, the formation of the precursor mixture and the injection of non-reactive gases can be repeated, thereby reducing the content of undissolved lithium precursors in the precipitate 80. Therefore, the yield of lithium precursors can be further improved.

[0111] For example, while repeatedly forming the precursor mixture and injecting the non-reactive gas, the injection amounts of the precipitate 80 and the non-reactive gas can be appropriately adjusted based on the solubility of the primary lithium precursor in the precipitate 80 and the capacity of the reactor 100.

[0112] For example, the injection volume of precipitate 80 and non-reactive gas can be constant, or it can be increased or decreased as multiple cycles are repeated.

[0113] In one embodiment, the precipitated primary transition metal precursor 70 can be collected from reactor 100 to form a transition metal precursor. For example, the primary transition metal precursor 70 can be reacted with an acid solution to form a transition metal precursor.

[0114] In one embodiment, sulfuric acid can be used as an acid solution. In this case, the transition metal precursor may include a transition metal sulfate. For example, transition metal sulfates may include NiSO4, MnSO4, CoSO4, etc.

Claims

1. A method for separating lithium precursors, comprising: The step of preparing a primary precursor mixture containing a primary lithium precursor and a primary transition metal precursor by reducing the positive electrode active material collected from a lithium secondary battery in a reactor; The process includes the steps of mixing the primary precursor mixture with a precipitate in the reactor to form an aqueous precursor mixture containing dissolved lithium hydroxide; and, after the step of forming the aqueous precursor mixture containing dissolved lithium hydroxide, injecting a non-reactive gas from the lower part of the reactor into the precursor mixture in a slurry or solution state, wherein the reactor is a fluidized bed reactor, wherein the upper part of the reactor includes an expansion section having an extended diameter or an extended width, and wherein the mass of the precipitate in the precursor mixture is 2 to 20 times the mass of the primary lithium precursor, wherein the step of injecting the non-reactive gas includes the step of reducing the linear velocity of the non-reactive gas at the upper part of the reactor, wherein the step of reducing the linear velocity of the non-reactive gas includes reducing the linear velocity of the non-reactive gas to 0.1 cm / s to 3 cm / s.

2. The method for separating lithium precursors according to claim 1, wherein the reduction reaction is carried out prior to the step of forming the precursor mixture in the reactor.

3. The method for separating lithium precursors according to claim 1, wherein the primary lithium precursor comprises lithium hydroxide.

4. The method for separating lithium precursors according to claim 3, wherein the primary lithium precursor further comprises lithium oxide or lithium carbonate.

5. The method for separating lithium precursors according to claim 1, wherein the step of forming the precursor mixture comprises selectively dissolving lithium hydroxide in the precipitate.

6. The method for separating lithium precursors according to claim 1, wherein the precipitate comprises water.

7. The method for separating lithium precursors according to claim 6, wherein the precipitate further comprises dimethyl carbonate or diethyl carbonate.

8. The method for separating lithium precursors according to claim 1, wherein the step of injecting the non-reactive gas comprises pulse injection of the non-reactive gas.

9. The method for separating lithium precursors according to claim 1, wherein the solubility of the non-reactive gas in the precipitate is less than 1.5 g / L.

10. The method for separating lithium precursors according to claim 1, wherein the non-reactive gas comprises at least one selected from nitrogen, neon, argon, krypton, and xenon.

11. The method for separating lithium precursors according to claim 1, wherein the steps of forming the precursor mixture and injecting the non-reactive gas are repeated in multiple cycles.

12. A system for separating lithium precursors, comprising a fluidized bed reactor, the fluidized bed reactor comprising: The reactor body incorporates a lithium precursor containing lithium hydroxide, formed by reducing positive electrode active material collected from a lithium secondary battery. A precipitate injection unit is used to inject precipitate into the reactor body; a gas injection unit is used to inject non-reactive gas into the lower part of the reactor body, thereby injecting non-reactive gas into the precursor mixture, wherein lithium hydroxide water is dissolved in the precipitate. And an expansion section extending from the upper part of the reactor body and having an expanded diameter or an expanded width, wherein the lithium precursor is obtained by separation using the method of claim 1.

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